import java.util.*;
import java.util.zip.*;
import java.util.List;
import java.util.regex.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.*;
import java.util.concurrent.locks.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import javax.swing.table.*;
import java.io.*;
import java.net.*;
import java.lang.reflect.*;
import java.lang.ref.*;
import java.lang.management.*;
import java.security.*;
import java.security.spec.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.imageio.*;
import java.math.*;


class main {
public static void main(final String[] args) throws Exception {
  List<String> l = new SynchronizedArrayList();
  l.add("Hello");
  l.add("World");
  assertEquals(ll("Hello", "World"), l);
  assertEquals(ll("Hello"), l.subList(0, 1));
  assertEquals(ll("World"), l.subList(0, 2).subList(1, 2));
  assertEquals(ll("World"), l.subList(1, 2).subList(0, 1));
  print("OK");
}
static <A> List<A> ll(A... a) {
  ArrayList l = new ArrayList(a.length);
  for (A x : a) l.add(x);
  return l;
}
static volatile StringBuffer local_log = new StringBuffer(); // not redirected
static volatile StringBuffer print_log = local_log; // might be redirected, e.g. to main bot

// in bytes - will cut to half that
static volatile int print_log_max = 1024*1024;
static volatile int local_log_max = 100*1024;
//static int print_maxLineLength = 0; // 0 = unset

static boolean print_silent; // total mute if set

static Object print_byThread_lock = new Object();
static volatile ThreadLocal<F1<String, Boolean>> print_byThread; // special handling by thread

static void print() {
  print("");
}

// slightly overblown signature to return original object...
static <A> A print(A o) {
  ping();
  if (print_silent) return o;
  String s = String.valueOf(o) + "\n";
  print_noNewLine(s);
  return o;
}

static void print_noNewLine(String s) {
  if (print_byThread != null) {
    F1<String, Boolean> f = print_byThread.get();
    if (f != null)
      if (isFalse(f.get(s))) return;
  }

  print_raw(s);
}

static void print_raw(String s) {
  s = fixNewLines(s);
  // TODO if (print_maxLineLength != 0)
  StringBuffer loc = local_log;
  StringBuffer buf = print_log;
  int loc_max = print_log_max;
  if (buf != loc && buf != null) {
    print_append(buf, s, print_log_max);
    loc_max = local_log_max;
  }
  if (loc != null) 
    print_append(loc, s, loc_max);
  System.out.print(s);
}

static void print(long l) {
  print(String.valueOf(l));
}

static void print(char c) {
  print(String.valueOf(c));
}

static void print_append(StringBuffer buf, String s, int max) {
  synchronized(buf) {
    buf.append(s);
    max /= 2;
    if (buf.length() > max) try {
      int newLength = max/2;
      int ofs = buf.length()-newLength;
      String newString = buf.substring(ofs);
      buf.setLength(0);
      buf.append("[...] ").append(newString);
    } catch (Exception e) {
      buf.setLength(0);
    }
  }
}
static RuntimeException asRuntimeException(Throwable t) {
  if (t instanceof Error)
    _handleError((Error) t);
  return t instanceof RuntimeException ? (RuntimeException) t : new RuntimeException(t);
}
static Map<Thread, Boolean> _registerThread_threads = newWeakHashMap();

static Thread _registerThread(Thread t) {
  _registerThread_threads.put(t, true);
  return t;
}

static void _registerThread() { _registerThread(Thread.currentThread()); }
static <A> A assertEquals(Object x, A y) {
  return assertEquals(null, x, y);
}

static <A> A assertEquals(String msg, Object x, A y) {
  if (!(x == null ? y == null : x.equals(y)))
    throw fail((msg != null ? msg + ": " : "") + y + " != " + x);
  return y;
}


static String fixNewLines(String s) {
  return s.replace("\r\n", "\n").replace("\r", "\n");
}
static RuntimeException fail() { throw new RuntimeException("fail"); }
static RuntimeException fail(Throwable e) { throw asRuntimeException(e); }
static RuntimeException fail(Object msg) { throw new RuntimeException(String.valueOf(msg)); }
static RuntimeException fail(String msg) { throw new RuntimeException(msg == null ? "" : msg); }
static RuntimeException fail(String msg, Throwable innerException) { throw new RuntimeException(msg, innerException); }

static AtomicLong _handleError_nonVMErrors = new AtomicLong();
static AtomicLong _handleError_vmErrors = new AtomicLong();
static AtomicLong _handleError_outOfMemoryErrors = new AtomicLong();
static volatile long _handleError_lastOutOfMemoryError;
static volatile Error _handleError_lastHardError;

static void _handleError(Error e) {
  if (!(e instanceof VirtualMachineError)) {
    incAtomicLong(_handleError_nonVMErrors);
    return;
  }
  
  print("\nHARD ERROR\n");
  printStackTrace2(e);
  print("\nHARD ERROR\n");
  _handleError_lastHardError = e;
  
  incAtomicLong(_handleError_vmErrors);
  if (e instanceof OutOfMemoryError) {
    incAtomicLong(_handleError_outOfMemoryErrors);
    _handleError_lastOutOfMemoryError = sysNow();
  }
}
static volatile boolean ping_pauseAll;
static int ping_sleep = 100; // poll pauseAll flag every 100
static volatile boolean ping_anyActions;
static Map<Thread, Object> ping_actions = newWeakHashMap();

// always returns true
static boolean ping() {
  if (ping_pauseAll || ping_anyActions) ping_impl();
  return true;
}

// returns true when it slept
static boolean ping_impl() { try {
  if (ping_pauseAll && !isAWTThread()) {
    do
      Thread.sleep(ping_sleep);
    while (ping_pauseAll);
    return true;
  }
  
  if (ping_anyActions) {
    Object action;
    synchronized(ping_actions) {
      action = ping_actions.get(currentThread());
      if (action instanceof Runnable)
        ping_actions.remove(currentThread());
      if (ping_actions.isEmpty()) ping_anyActions = false;
    }
    
    if (action instanceof Runnable)
      ((Runnable) action).run();
    else if (eq(action, "cancelled"))
      throw fail("Thread cancelled.");
  }
  
  return false;
} catch (Exception __e) { throw rethrow(__e); } }
static boolean isFalse(Object o) {
  return eq(false, o);
}
static <A, B> Map<A, B> newWeakHashMap() {
  return _registerWeakMap(synchroMap(new WeakHashMap()));
}


static RuntimeException rethrow(Throwable e) {
  throw asRuntimeException(e);
}
static Map synchroMap() {
  return synchroHashMap();
}

static <A, B> Map<A, B> synchroMap(Map<A, B> map) {
  return Collections.synchronizedMap(map);
}
static Thread currentThread() {
  return Thread.currentThread();
}
static boolean eq(Object a, Object b) {
  return a == null ? b == null : a == b || a.equals(b);
}
static long sysNow() {
  return System.nanoTime()/1000000;
}
static Throwable printStackTrace2(Throwable e) {
  // we go to system.out now - system.err is nonsense
  print(getStackTrace2(e));
  return e;
}

static void printStackTrace2() {
  printStackTrace2(new Throwable());
}

static void printStackTrace2(String msg) {
  printStackTrace2(new Throwable(msg));
}

/*static void printStackTrace2(S indent, Throwable e) {
  if (endsWithLetter(indent)) indent += " ";
  printIndent(indent, getStackTrace2(e));
}*/
static List _registerWeakMap_preList;

static <A> A _registerWeakMap(A map) {
  if (javax() == null) {
    // We're in class init
    if (_registerWeakMap_preList == null) _registerWeakMap_preList = synchroList();
    _registerWeakMap_preList.add(map);
    return map;
  }
  
  try {
    call(javax(), "_registerWeakMap", map);
  } catch (Throwable e) {
    printException(e);
    print("Upgrade JavaX!!");
  }
  return map;
}

static void _onLoad_registerWeakMap() {
  assertNotNull(javax());
  if (_registerWeakMap_preList == null) return;
  for (Object o : _registerWeakMap_preList)
    _registerWeakMap(o);
  _registerWeakMap_preList = null;
}
static void incAtomicLong(AtomicLong l) {
  l.incrementAndGet();
}
// TODO: test if android complains about this
static boolean isAWTThread() {
  if (isAndroid()) return false;
  if (isHeadless()) return false;
  return isAWTThread_awt();
}

static boolean isAWTThread_awt() {
  return SwingUtilities.isEventDispatchThread();
}


static Boolean isHeadless_cache;

static boolean isHeadless() {
  if (isHeadless_cache != null) return isHeadless_cache;
  if (GraphicsEnvironment.isHeadless()) return isHeadless_cache = true;
  
  // Also check if AWT actually works.
  // If DISPLAY variable is set but no X server up, this will notice.
  
  try {
    SwingUtilities.isEventDispatchThread();
    return isHeadless_cache = false;
  } catch (Throwable e) { return isHeadless_cache = true; }
}
static Class javax() {
  return getJavaX();
}
static <A> A assertNotNull(A a) {
  assertTrue(a != null);
  return a;
}

static <A> A assertNotNull(String msg, A a) {
  assertTrue(msg, a != null);
  return a;
}
static <A> List<A> synchroList() {
  return Collections.synchronizedList(new ArrayList<A>());
}

static <A> List<A> synchroList(List<A> l) {
  return Collections.synchronizedList(l);
}

static String getStackTrace2(Throwable throwable) {
  return hideCredentials(getStackTrace(throwable) + replacePrefix("java.lang.RuntimeException: ", "FAIL: ",
    hideCredentials(str(getInnerException(throwable)))) + "\n");
}
static void printException(Throwable e) {
  printStackTrace(e);
}
static Object call(Object o) {
  return callFunction(o);
}

// varargs assignment fixer for a single string array argument
static Object call(Object o, String method, String[] arg) {
  return call(o, method, new Object[] {arg});
}

static Object call(Object o, String method, Object... args) {
  try {
    if (o instanceof Class) {
      Method m = call_findStaticMethod((Class) o, method, args, false);
      m.setAccessible(true);
      return m.invoke(null, args);
    } else {
      Method m = call_findMethod(o, method, args, false);
      m.setAccessible(true);
      return m.invoke(o, args);
    }
  } catch (Exception e) {
    throw e instanceof RuntimeException ? (RuntimeException) e : new RuntimeException(e);
  }
}

static Method call_findStaticMethod(Class c, String method, Object[] args, boolean debug) {
  Class _c = c;
  while (c != null) {
    for (Method m : c.getDeclaredMethods()) {
      if (debug)
        System.out.println("Checking method " + m.getName() + " with " + m.getParameterTypes().length + " parameters");;
      if (!m.getName().equals(method)) {
        if (debug) System.out.println("Method name mismatch: " + method);
        continue;
      }

      if ((m.getModifiers() & java.lang.reflect.Modifier.STATIC) == 0 || !call_checkArgs(m, args, debug))
        continue;

      return m;
    }
    c = c.getSuperclass();
  }
  throw new RuntimeException("Method '" + method + "' (static) with " + args.length + " parameter(s) not found in " + _c.getName());
}

static Method call_findMethod(Object o, String method, Object[] args, boolean debug) {
  Class c = o.getClass();
  while (c != null) {
    for (Method m : c.getDeclaredMethods()) {
      if (debug)
        System.out.println("Checking method " + m.getName() + " with " + m.getParameterTypes().length + " parameters");;
      if (m.getName().equals(method) && call_checkArgs(m, args, debug))
        return m;
    }
    c = c.getSuperclass();
  }
  throw new RuntimeException("Method '" + method + "' (non-static) with " + args.length + " parameter(s) not found in " + o.getClass().getName());
}

private static boolean call_checkArgs(Method m, Object[] args, boolean debug) {
  Class<?>[] types = m.getParameterTypes();
  if (types.length != args.length) {
    if (debug)
      System.out.println("Bad parameter length: " + args.length + " vs " + types.length);
    return false;
  }
  for (int i = 0; i < types.length; i++)
    if (!(args[i] == null || isInstanceX(types[i], args[i]))) {
      if (debug)
        System.out.println("Bad parameter " + i + ": " + args[i] + " vs " + types[i]);
      return false;
    }
  return true;
}
static Map synchroHashMap() {
  return Collections.synchronizedMap(new HashMap());
}

static int isAndroid_flag;

static boolean isAndroid() {
  if (isAndroid_flag == 0)
    isAndroid_flag = System.getProperty("java.vendor").toLowerCase().indexOf("android") >= 0 ? 1 : -1;
  return isAndroid_flag > 0;
}



static Object callFunction(Object f, Object... args) {
  return callF(f, args);
}
static String getStackTrace(Throwable throwable) {
  lastException(throwable);
  StringWriter writer = new StringWriter();
  throwable.printStackTrace(new PrintWriter(writer));
  return hideCredentials(writer.toString());
}
static void assertTrue(Object o) {
  if (!(eq(o, true) || isTrue(pcallF(o))))
    throw fail(str(o));
}
  
static boolean assertTrue(String msg, boolean b) {
  if (!b)
    throw fail(msg);
  return b;
}

static boolean assertTrue(boolean b) {
  if (!b)
    throw fail("oops");
  return b;
}
static String hideCredentials(URL url) { return url == null ? null : hideCredentials(str(url)); }

static String hideCredentials(String url) {
  return url.replaceAll("([&?])_pass=[^&\\s\"]*", "$1_pass=<hidden>");
}
// extended over Class.isInstance() to handle primitive types
static boolean isInstanceX(Class type, Object arg) {
  if (type == boolean.class) return arg instanceof Boolean;
  if (type == int.class) return arg instanceof Integer;
  if (type == long.class) return arg instanceof Long;
  if (type == float.class) return arg instanceof Float;
  if (type == short.class) return arg instanceof Short;
  if (type == char.class) return arg instanceof Character;
  if (type == byte.class) return arg instanceof Byte;
  if (type == double.class) return arg instanceof Double;
  return type.isInstance(arg);
}
static Class __javax;

static Class getJavaX() {
  return __javax;
}
static Throwable printStackTrace(Throwable e) {
  // we go to system.out now - system.err is nonsense
  print(getStackTrace(e));
  return e;
}

static void printStackTrace() {
  printStackTrace(new Throwable());
}

static void printStackTrace(String msg) {
  printStackTrace(new Throwable(msg));
}

/*static void printStackTrace(S indent, Throwable e) {
  if (endsWithLetter(indent)) indent += " ";
  printIndent(indent, getStackTrace(e));
}*/
static String replacePrefix(String prefix, String replacement, String s) {
  if (!startsWith(s, prefix)) return s;
  return replacement + substring(s, l(prefix));
}
static Throwable getInnerException(Throwable e) {
  while (e.getCause() != null)
    e = e.getCause();
  return e;
}
static String str(Object o) {
  return o == null ? "null" : o.toString();
}

static String str(char[] c) {
  return new String(c);
}


static volatile Throwable lastException_lastException;

static Throwable lastException() {
  return lastException_lastException;
}

static void lastException(Throwable e) {
  lastException_lastException = e;
}
static Object pcallF(Object f, Object... args) {
  return pcallFunction(f, args);
}


static <A, B> B pcallF(F1<A, B> f, A a) { try {
  return f == null ? null : f.get(a);
} catch (Throwable __e) { return null; } }

static WeakHashMap<Class, ArrayList<Method>> callF_cache = new WeakHashMap();




  static <A, B> B callF(F1<A, B> f, A a) {
    return f == null ? null : f.get(a);
  }


static Object callF(Object f, Object... args) { try {
  if (f instanceof String)
    return callMC((String) f, args);
  if (f instanceof Runnable) {
    ((Runnable) f).run();
    return null;
  }
  if (f == null) return null;
  
  Class c = f.getClass();
  ArrayList<Method> methods;
  synchronized(callF_cache) {
    methods = callF_cache.get(c);
    if (methods == null)
      methods = callF_makeCache(c);
  }
  
  int n = l(methods);
  if (n == 0) throw fail("No get method in " + getClassName(c));
  if (n == 1) return methods.get(0).invoke(f, args);
  for (int i = 0; i < n; i++) {
    Method m = methods.get(i);
    if (call_checkArgs(m, args, false))
      return m.invoke(f, args);
  }
  throw fail("No matching get method in " + getClassName(c));
} catch (Exception __e) { throw rethrow(__e); } }

// used internally
static ArrayList<Method> callF_makeCache(Class c) {
  ArrayList<Method> l = new ArrayList();
  Class _c = c;
  do {
    for (Method m : _c.getDeclaredMethods())
      if (m.getName().equals("get")) {
        m.setAccessible(true);
        l.add(m);
      }
    if (!l.isEmpty()) break;
    _c = _c.getSuperclass();
  } while (_c != null);
  callF_cache.put(c, l);
  return l;
}
static String substring(String s, int x) {
  return substring(s, x, l(s));
}

static String substring(String s, int x, int y) {
  if (s == null) return null;
  if (x < 0) x = 0;
  if (x > s.length()) return "";
  if (y < x) y = x;
  if (y > s.length()) y = s.length();
  return s.substring(x, y);
}


static int l(Object[] a) { return a == null ? 0 : a.length; }
static int l(boolean[] a) { return a == null ? 0 : a.length; }
static int l(byte[] a) { return a == null ? 0 : a.length; }
static int l(int[] a) { return a == null ? 0 : a.length; }
static int l(float[] a) { return a == null ? 0 : a.length; }
static int l(char[] a) { return a == null ? 0 : a.length; }
static int l(Collection c) { return c == null ? 0 : c.size(); }
static int l(Map m) { return m == null ? 0 : m.size(); }
static int l(CharSequence s) { return s == null ? 0 : s.length(); } static long l(File f) { return f == null ? 0 : f.length(); }

static int l(Object o) {
  return o instanceof String ? l((String) o)
    : o instanceof Map ? l((Map) o)
    : l((Collection) o); // incomplete
}




static boolean isTrue(Object o) {
  if (o instanceof Boolean)
    return ((Boolean) o).booleanValue();
  if (o == null) return false;
  throw fail(getClassName(o));
}
static boolean startsWith(String a, String b) {
  return a != null && a.startsWith(b);
}

static boolean startsWith(String a, char c) {
  return nempty(a) && a.charAt(0) == c;
}



static boolean startsWith(List a, List b) {
  if (a == null || l(b) > l(a)) return false;
  for (int i = 0; i < l(b); i++)
    if (neq(a.get(i), b.get(i)))
      return false;
  return true;
}




static HashMap<String, List<Method>> callMC_cache = new HashMap();
static String callMC_key;
static Method callMC_value;

// varargs assignment fixer for a single string array argument
static Object callMC(String method, String[] arg) {
  return callMC(method, new Object[] {arg});
}

static Object callMC(String method, Object... args) { try {
  Method me;
  if (callMC_cache == null) callMC_cache = new HashMap(); // initializer time workaround
  synchronized(callMC_cache) {
    me = method == callMC_key ? callMC_value : null;
  }
  if (me != null) try {
    return me.invoke(null, args);
  } catch (IllegalArgumentException e) {
    throw new RuntimeException("Can't call " + me + " with arguments " + classNames(args), e);
  }

  List<Method> m;
  synchronized(callMC_cache) {
    m = callMC_cache.get(method);
  }
  if (m == null) {
    if (callMC_cache.isEmpty()) {
      callMC_makeCache();
      m = callMC_cache.get(method);
    }
    if (m == null) throw fail("Method named " + method + " not found in main");
  }
  int n = m.size();
  if (n == 1) {
    me = m.get(0);
    synchronized(callMC_cache) {
      callMC_key = method;
      callMC_value = me;
    }
    try {
      return me.invoke(null, args);
    } catch (IllegalArgumentException e) {
      throw new RuntimeException("Can't call " + me + " with arguments " + classNames(args), e);
    }
  }
  for (int i = 0; i < n; i++) {
    me = m.get(i);
    if (call_checkArgs(me, args, false))
      return me.invoke(null, args);
  }
  throw fail("No method called " + method + " with matching arguments found in main");
} catch (Exception __e) { throw rethrow(__e); } }

static void callMC_makeCache() {
  synchronized(callMC_cache) {
    callMC_cache.clear();
    Class _c = (Class) mc(), c = _c;
    while (c != null) {
      for (Method m : c.getDeclaredMethods())
        if ((m.getModifiers() & java.lang.reflect.Modifier.STATIC) != 0) {
          m.setAccessible(true);
          multiMapPut(callMC_cache, m.getName(), m);
        }
      c = c.getSuperclass();
    }
  }
}
static boolean neq(Object a, Object b) {
  return !eq(a, b);
}
static String getClassName(Object o) {
  return o == null ? "null" : o instanceof Class ? ((Class) o).getName() : o.getClass().getName();
}
static boolean nempty(Collection c) {
  return !isEmpty(c);
}

static boolean nempty(CharSequence s) {
  return !isEmpty(s);
}

static boolean nempty(Object[] o) {
  return !isEmpty(o);
}

static boolean nempty(Map m) {
  return !isEmpty(m);
}

static boolean nempty(Iterator i) {
  return i != null && i.hasNext();
}
static Object pcallFunction(Object f, Object... args) {
  try { return callFunction(f, args); } catch (Throwable __e) { printStackTrace2(__e); }
  return null;
}


static List<String> classNames(Collection l) {
  return getClassNames(l);
}

static List<String> classNames(Object[] l) {
  return getClassNames(Arrays.asList(l));
}
static Class mc() {
  return main.class;
}
static <A, B> void multiMapPut(Map<A, List<B>> map, A a, B b) {
  List<B> l = map.get(a);
  if (l == null)
    map.put(a, l = new ArrayList());
  l.add(b);
}
static boolean isEmpty(Collection c) {
  return c == null || c.isEmpty();
}

static boolean isEmpty(CharSequence s) {
  return s == null || s.length() == 0;
}

static boolean isEmpty(Object[] a) {
  return a == null || a.length == 0;
}

static boolean isEmpty(Map map) {
  return map == null || map.isEmpty();
}


static List<String> getClassNames(Collection l) {
  List<String> out = new ArrayList();
  if (l != null) for (Object o : l)
    out.add(o == null ? null : getClassName(o));
  return out;
}


static abstract class F1<A, B> {
  abstract B get(A a);
}// Modified from java.util.ArrayList
 
static class SynchronizedArrayList<A> extends SynchronizedArrayList_Base<A> implements RandomAccess, Cloneable {
  private static final int DEFAULT_CAPACITY = 10;
  private static final Object[] EMPTY_ELEMENTDATA = {};
  private static final Object[] DEFAULTCAPACITY_EMPTY_ELEMENTDATA = {};
  transient Object[] elementData; // non-private to simplify nested class access
  private int size;

  SynchronizedArrayList(int initialCapacity) {
      if (initialCapacity > 0) {
          this.elementData = new Object[initialCapacity];
      } else if (initialCapacity == 0) {
          this.elementData = EMPTY_ELEMENTDATA;
      } else {
          throw new IllegalArgumentException("Illegal Capacity: "+
                                             initialCapacity);
      }
  }

  SynchronizedArrayList() {
      this.elementData = DEFAULTCAPACITY_EMPTY_ELEMENTDATA;
  }

  SynchronizedArrayList(Collection<? extends A> c) {
      elementData = c.toArray();
      if ((size = elementData.length) != 0) {
          // c.toArray might (incorrectly) not return Object[] (see 6260652)
          if (elementData.getClass() != Object[].class)
              elementData = Arrays.copyOf(elementData, size, Object[].class);
      } else {
          // replace with empty array.
          this.elementData = EMPTY_ELEMENTDATA;
      }
  }

  public void trimToSize() {
      modCount++;
      if (size < elementData.length) {
          elementData = (size == 0)
            ? EMPTY_ELEMENTDATA
            : Arrays.copyOf(elementData, size);
      }
  }

  public void ensureCapacity(int minCapacity) {
      int minExpand = (elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA)
          // any size if not default element table
          ? 0
          // larger than default for default empty table. It's already
          // supposed to be at default size.
          : DEFAULT_CAPACITY;

      if (minCapacity > minExpand) {
          ensureExplicitCapacity(minCapacity);
      }
  }

  private void ensureCapacityInternal(int minCapacity) {
      if (elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA) {
          minCapacity = Math.max(DEFAULT_CAPACITY, minCapacity);
      }

      ensureExplicitCapacity(minCapacity);
  }

  private void ensureExplicitCapacity(int minCapacity) {
      modCount++;

      // overflow-conscious code
      if (minCapacity - elementData.length > 0)
          grow(minCapacity);
  }

  private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;

  private void grow(int minCapacity) {
      // overflow-conscious code
      int oldCapacity = elementData.length;
      int newCapacity = oldCapacity + (oldCapacity >> 1);
      if (newCapacity - minCapacity < 0)
          newCapacity = minCapacity;
      if (newCapacity - MAX_ARRAY_SIZE > 0)
          newCapacity = hugeCapacity(minCapacity);
      // minCapacity is usually close to size, so this is a win:
      elementData = Arrays.copyOf(elementData, newCapacity);
  }

  private static int hugeCapacity(int minCapacity) {
      if (minCapacity < 0) // overflow
          throw new OutOfMemoryError();
      return (minCapacity > MAX_ARRAY_SIZE) ?
          Integer.MAX_VALUE :
          MAX_ARRAY_SIZE;
  }

  public int size() {
      return size;
  }

  public boolean isEmpty() {
      return size == 0;
  }

  public boolean contains(Object o) {
      return indexOf(o) >= 0;
  }

  public int indexOf(Object o) {
      if (o == null) {
          for (int i = 0; i < size; i++)
              if (elementData[i]==null)
                  return i;
      } else {
          for (int i = 0; i < size; i++)
              if (o.equals(elementData[i]))
                  return i;
      }
      return -1;
  }

  public int lastIndexOf(Object o) {
      if (o == null) {
          for (int i = size-1; i >= 0; i--)
              if (elementData[i]==null)
                  return i;
      } else {
          for (int i = size-1; i >= 0; i--)
              if (o.equals(elementData[i]))
                  return i;
      }
      return -1;
  }

  public Object clone() {
    return new SynchronizedArrayList(this);
  }

  public Object[] toArray() {
      return Arrays.copyOf(elementData, size);
  }

  @SuppressWarnings("unchecked")
  public <T> T[] toArray(T[] a) {
      if (a.length < size)
          // Make a new array of a's runtime type, but my contents:
          return (T[]) Arrays.copyOf(elementData, size, a.getClass());
      System.arraycopy(elementData, 0, a, 0, size);
      if (a.length > size)
          a[size] = null;
      return a;
  }

  // Positional Access Operations

  @SuppressWarnings("unchecked")
  A elementData(int index) {
      return (A) elementData[index];
  }

  public A get(int index) {
      rangeCheck(index);

      return elementData(index);
  }

  public A set(int index, A element) {
      rangeCheck(index);

      A oldValue = elementData(index);
      elementData[index] = element;
      return oldValue;
  }

  public boolean add(A e) {
      ensureCapacityInternal(size + 1);  // Increments modCount!!
      elementData[size++] = e;
      return true;
  }

  public void add(int index, A element) {
      rangeCheckForAdd(index);

      ensureCapacityInternal(size + 1);  // Increments modCount!!
      System.arraycopy(elementData, index, elementData, index + 1,
                       size - index);
      elementData[index] = element;
      size++;
  }

  public A remove(int index) {
      rangeCheck(index);

      modCount++;
      A oldValue = elementData(index);

      int numMoved = size - index - 1;
      if (numMoved > 0)
          System.arraycopy(elementData, index+1, elementData, index,
                           numMoved);
      elementData[--size] = null; // clear to let GC do its work

      return oldValue;
  }

  public boolean remove(Object o) {
      if (o == null) {
          for (int index = 0; index < size; index++)
              if (elementData[index] == null) {
                  fastRemove(index);
                  return true;
              }
      } else {
          for (int index = 0; index < size; index++)
              if (o.equals(elementData[index])) {
                  fastRemove(index);
                  return true;
              }
      }
      return false;
  }

  private void fastRemove(int index) {
      modCount++;
      int numMoved = size - index - 1;
      if (numMoved > 0)
          System.arraycopy(elementData, index+1, elementData, index,
                           numMoved);
      elementData[--size] = null; // clear to let GC do its work
  }

  public void clear() {
      modCount++;

      // clear to let GC do its work
      for (int i = 0; i < size; i++)
          elementData[i] = null;

      size = 0;
  }

  public boolean addAll(Collection<? extends A> c) {
      Object[] a = c.toArray();
      int numNew = a.length;
      ensureCapacityInternal(size + numNew);  // Increments modCount
      System.arraycopy(a, 0, elementData, size, numNew);
      size += numNew;
      return numNew != 0;
  }

  public boolean addAll(int index, Collection<? extends A> c) {
      rangeCheckForAdd(index);

      Object[] a = c.toArray();
      int numNew = a.length;
      ensureCapacityInternal(size + numNew);  // Increments modCount

      int numMoved = size - index;
      if (numMoved > 0)
          System.arraycopy(elementData, index, elementData, index + numNew,
                           numMoved);

      System.arraycopy(a, 0, elementData, index, numNew);
      size += numNew;
      return numNew != 0;
  }

  public void removeRange(int fromIndex, int toIndex) {
      modCount++;
      int numMoved = size - toIndex;
      System.arraycopy(elementData, toIndex, elementData, fromIndex,
                       numMoved);

      // clear to let GC do its work
      int newSize = size - (toIndex-fromIndex);
      for (int i = newSize; i < size; i++) {
          elementData[i] = null;
      }
      size = newSize;
  }

  private void rangeCheck(int index) {
      if (index >= size)
          throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
  }

  private void rangeCheckForAdd(int index) {
      if (index > size || index < 0)
          throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
  }

  /**
   * Constructs an IndexOutOfBoundsException detail message.
   * Of the many possible refactorings of the error handling code,
   * this "outlining" performs best with both server and client VMs.
   */
  private String outOfBoundsMsg(int index) {
      return "Index: "+index+", Size: "+size;
  }

  public boolean removeAll(Collection<?> c) {
      Objects.requireNonNull(c);
      return batchRemove(c, false);
  }

  public boolean retainAll(Collection<?> c) {
      Objects.requireNonNull(c);
      return batchRemove(c, true);
  }

  private boolean batchRemove(Collection<?> c, boolean complement) {
      final Object[] elementData = this.elementData;
      int r = 0, w = 0;
      boolean modified = false;
      try {
          for (; r < size; r++)
              if (c.contains(elementData[r]) == complement)
                  elementData[w++] = elementData[r];
      } finally {
          // Preserve behavioral compatibility with AbstractCollection,
          // even if c.contains() throws.
          if (r != size) {
              System.arraycopy(elementData, r,
                               elementData, w,
                               size - r);
              w += size - r;
          }
          if (w != size) {
              // clear to let GC do its work
              for (int i = w; i < size; i++)
                  elementData[i] = null;
              modCount += size - w;
              size = w;
              modified = true;
          }
      }
      return modified;
  }

  /**
   * Save the state of the <tt>ArrayList</tt> instance to a stream (that
   * is, serialize it).
   *
   * @serialData The length of the array backing the <tt>ArrayList</tt>
   *             instance is emitted (int), followed by all of its elements
   *             (each an <tt>Object</tt>) in the proper order.
   */
  private void writeObject(java.io.ObjectOutputStream s)
      throws java.io.IOException{
      // Write out element count, and any hidden stuff
      int expectedModCount = modCount;
      s.defaultWriteObject();

      // Write out size as capacity for behavioural compatibility with clone()
      s.writeInt(size);

      // Write out all elements in the proper order.
      for (int i=0; i<size; i++) {
          s.writeObject(elementData[i]);
      }

      if (modCount != expectedModCount) {
          throw new ConcurrentModificationException();
      }
  }

  /**
   * Reconstitute the <tt>ArrayList</tt> instance from a stream (that is,
   * deserialize it).
   */
  private void readObject(java.io.ObjectInputStream s)
      throws java.io.IOException, ClassNotFoundException {
      elementData = EMPTY_ELEMENTDATA;

      // Read in size, and any hidden stuff
      s.defaultReadObject();

      // Read in capacity
      s.readInt(); // ignored

      if (size > 0) {
          // be like clone(), allocate array based upon size not capacity
          ensureCapacityInternal(size);

          Object[] a = elementData;
          // Read in all elements in the proper order.
          for (int i=0; i<size; i++) {
              a[i] = s.readObject();
          }
      }
  }

  /**
   * Returns a list iterator over the elements in this list (in proper
   * sequence), starting at the specified position in the list.
   * The specified index indicates the first element that would be
   * returned by an initial call to {@link ListIterator#next next}.
   * An initial call to {@link ListIterator#previous previous} would
   * return the element with the specified index minus one.
   *
   * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
   *
   * @throws IndexOutOfBoundsException {@inheritDoc}
   */
  public ListIterator<A> listIterator(int index) {
      if (index < 0 || index > size)
          throw new IndexOutOfBoundsException("Index: "+index);
      return new ListItr(index);
  }

  /**
   * Returns a list iterator over the elements in this list (in proper
   * sequence).
   *
   * <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
   *
   * @see #listIterator(int)
   */
  public ListIterator<A> listIterator() {
      return new ListItr(0);
  }

  /**
   * Returns an iterator over the elements in this list in proper sequence.
   *
   * <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
   *
   * @return an iterator over the elements in this list in proper sequence
   */
  public Iterator<A> iterator() {
      return new Itr();
  }

  /**
   * An optimized version of AbstractList.Itr
   */
  private class Itr implements Iterator<A> {
      int cursor;       // index of next element to return
      int lastRet = -1; // index of last element returned; -1 if no such
      int expectedModCount = modCount;

      public boolean hasNext() {
          return cursor != size;
      }

      @SuppressWarnings("unchecked")
      public A next() {
          checkForComodification();
          int i = cursor;
          if (i >= size)
              throw new NoSuchElementException();
          Object[] elementData = SynchronizedArrayList.this.elementData;
          if (i >= elementData.length)
              throw new ConcurrentModificationException();
          cursor = i + 1;
          return (A) elementData[lastRet = i];
      }

      public void remove() {
          if (lastRet < 0)
              throw new IllegalStateException();
          checkForComodification();

          try {
              SynchronizedArrayList.this.remove(lastRet);
              cursor = lastRet;
              lastRet = -1;
              expectedModCount = modCount;
          } catch (IndexOutOfBoundsException ex) {
              throw new ConcurrentModificationException();
          }
      }

      final void checkForComodification() {
          if (modCount != expectedModCount)
              throw new ConcurrentModificationException();
      }
  }

  /**
   * An optimized version of AbstractList.ListItr
   */
  private class ListItr extends Itr implements ListIterator<A> {
      ListItr(int index) {
          super();
          cursor = index;
      }

      public boolean hasPrevious() {
          return cursor != 0;
      }

      public int nextIndex() {
          return cursor;
      }

      public int previousIndex() {
          return cursor - 1;
      }

      @SuppressWarnings("unchecked")
      public A previous() {
          checkForComodification();
          int i = cursor - 1;
          if (i < 0)
              throw new NoSuchElementException();
          Object[] elementData = SynchronizedArrayList.this.elementData;
          if (i >= elementData.length)
              throw new ConcurrentModificationException();
          cursor = i;
          return (A) elementData[lastRet = i];
      }

      public void set(A e) {
          if (lastRet < 0)
              throw new IllegalStateException();
          checkForComodification();

          try {
              SynchronizedArrayList.this.set(lastRet, e);
          } catch (IndexOutOfBoundsException ex) {
              throw new ConcurrentModificationException();
          }
      }

      public void add(A e) {
          checkForComodification();

          try {
              int i = cursor;
              SynchronizedArrayList.this.add(i, e);
              cursor = i + 1;
              lastRet = -1;
              expectedModCount = modCount;
          } catch (IndexOutOfBoundsException ex) {
              throw new ConcurrentModificationException();
          }
      }
  }

  public List<A> subList(int fromIndex, int toIndex) {
      subListRangeCheck(fromIndex, toIndex, size);
      return new SubList(this, 0, fromIndex, toIndex);
  }

  static void subListRangeCheck(int fromIndex, int toIndex, int size) {
      if (fromIndex < 0)
          throw new IndexOutOfBoundsException("fromIndex = " + fromIndex);
      if (toIndex > size)
          throw new IndexOutOfBoundsException("toIndex = " + toIndex);
      if (fromIndex > toIndex)
          throw new IllegalArgumentException("fromIndex(" + fromIndex +
                                             ") > toIndex(" + toIndex + ")");
  }

  private class SubList extends SynchronizedArrayList_Base<A> implements RandomAccess {
      private final SynchronizedArrayList_Base<A> parent;
      private final int parentOffset;
      private final int offset;
      int size;

      SubList(SynchronizedArrayList_Base<A> parent,
              int offset, int fromIndex, int toIndex) {
          this.parent = parent;
          this.parentOffset = fromIndex;
          this.offset = offset + fromIndex;
          this.size = toIndex - fromIndex;
          this.modCount = SynchronizedArrayList.this.modCount;
      }

      public A set(int index, A e) {
          rangeCheck(index);
          checkForComodification();
          A oldValue = SynchronizedArrayList.this.elementData(offset + index);
          SynchronizedArrayList.this.elementData[offset + index] = e;
          return oldValue;
      }

      public A get(int index) {
          rangeCheck(index);
          checkForComodification();
          return SynchronizedArrayList.this.elementData(offset + index);
      }

      public int size() {
          checkForComodification();
          return this.size;
      }

      public void add(int index, A e) {
          rangeCheckForAdd(index);
          checkForComodification();
          parent.add(parentOffset + index, e);
          this.modCount = parent.modCount();
          this.size++;
      }

      public A remove(int index) {
          rangeCheck(index);
          checkForComodification();
          A result = parent.remove(parentOffset + index);
          this.modCount = parent.modCount();
          this.size--;
          return result;
      }

      public void removeRange(int fromIndex, int toIndex) {
          checkForComodification();
          parent.removeRange(parentOffset + fromIndex,
                             parentOffset + toIndex);
          this.modCount = parent.modCount();
          this.size -= toIndex - fromIndex;
      }

      public boolean addAll(Collection<? extends A> c) {
          return addAll(this.size, c);
      }

      public boolean addAll(int index, Collection<? extends A> c) {
          rangeCheckForAdd(index);
          int cSize = c.size();
          if (cSize==0)
              return false;

          checkForComodification();
          parent.addAll(parentOffset + index, c);
          this.modCount = parent.modCount();
          this.size += cSize;
          return true;
      }

      public Iterator<A> iterator() {
          return listIterator();
      }

      public ListIterator<A> listIterator(final int index) {
          checkForComodification();
          rangeCheckForAdd(index);
          final int offset = this.offset;

          return new ListIterator<A>() {
              int cursor = index;
              int lastRet = -1;
              int expectedModCount = SynchronizedArrayList.this.modCount;

              public boolean hasNext() {
                  return cursor != SubList.this.size;
              }

              @SuppressWarnings("unchecked")
              public A next() {
                  checkForComodification();
                  int i = cursor;
                  if (i >= SubList.this.size)
                      throw new NoSuchElementException();
                  Object[] elementData = SynchronizedArrayList.this.elementData;
                  if (offset + i >= elementData.length)
                      throw new ConcurrentModificationException();
                  cursor = i + 1;
                  return (A) elementData[offset + (lastRet = i)];
              }

              public boolean hasPrevious() {
                  return cursor != 0;
              }

              @SuppressWarnings("unchecked")
              public A previous() {
                  checkForComodification();
                  int i = cursor - 1;
                  if (i < 0)
                      throw new NoSuchElementException();
                  Object[] elementData = SynchronizedArrayList.this.elementData;
                  if (offset + i >= elementData.length)
                      throw new ConcurrentModificationException();
                  cursor = i;
                  return (A) elementData[offset + (lastRet = i)];
              }

              public int nextIndex() {
                  return cursor;
              }

              public int previousIndex() {
                  return cursor - 1;
              }

              public void remove() {
                  if (lastRet < 0)
                      throw new IllegalStateException();
                  checkForComodification();

                  try {
                      SubList.this.remove(lastRet);
                      cursor = lastRet;
                      lastRet = -1;
                      expectedModCount = SynchronizedArrayList.this.modCount;
                  } catch (IndexOutOfBoundsException ex) {
                      throw new ConcurrentModificationException();
                  }
              }

              public void set(A e) {
                  if (lastRet < 0)
                      throw new IllegalStateException();
                  checkForComodification();

                  try {
                      SynchronizedArrayList.this.set(offset + lastRet, e);
                  } catch (IndexOutOfBoundsException ex) {
                      throw new ConcurrentModificationException();
                  }
              }

              public void add(A e) {
                  checkForComodification();

                  try {
                      int i = cursor;
                      SubList.this.add(i, e);
                      cursor = i + 1;
                      lastRet = -1;
                      expectedModCount = SynchronizedArrayList.this.modCount;
                  } catch (IndexOutOfBoundsException ex) {
                      throw new ConcurrentModificationException();
                  }
              }

              final void checkForComodification() {
                  if (expectedModCount != SynchronizedArrayList.this.modCount)
                      throw new ConcurrentModificationException();
              }
          };
      }

      public List<A> subList(int fromIndex, int toIndex) {
          subListRangeCheck(fromIndex, toIndex, size);
          return new SubList(parent, offset, fromIndex, toIndex);
      }

      private void rangeCheck(int index) {
          if (index < 0 || index >= this.size)
              throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
      }

      private void rangeCheckForAdd(int index) {
          if (index < 0 || index > this.size)
              throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
      }

      private String outOfBoundsMsg(int index) {
          return "Index: "+index+", Size: "+this.size;
      }

      private void checkForComodification() {
          if (SynchronizedArrayList.this.modCount != this.modCount)
              throw new ConcurrentModificationException();
      }
  }

  @Override
  @SuppressWarnings("unchecked")
  public void sort(Comparator<? super A> c) {
      final int expectedModCount = modCount;
      Arrays.sort((A[]) elementData, 0, size, c);
      if (modCount != expectedModCount) {
          throw new ConcurrentModificationException();
      }
      modCount++;
  }
}


abstract static class SynchronizedArrayList_Base<A> extends AbstractList<A> {
  final int modCount() { return modCount; }
  public void removeRange(int i, int j) { super.removeRange(i, j); }
}

static <A> Iterator<A> iterator(Collection<A> c) {
  return c == null ? emptyIterator() : c.iterator();
}
static <A> int indexOf(List<A> l, A a, int startIndex) {
  if (l == null) return -1;
  for (int i = startIndex; i < l(l); i++)
    if (eq(l.get(i), a))
      return i;
  return -1;
}

static <A> int indexOf(List<A> l, int startIndex, A a) {
  return indexOf(l, a, startIndex);
}

static <A> int indexOf(List<A> l, A a) {
  if (l == null) return -1;
  return l.indexOf(a);
}

static int indexOf(String a, String b) {
  return a == null || b == null ? -1 : a.indexOf(b);
}

static int indexOf(String a, String b, int i) {
  return a == null || b == null ? -1 : a.indexOf(b, i);
}

static int indexOf(String a, char b) {
  return a == null ? -1 : a.indexOf(b);
}

static int indexOf(String a, char b, int i) {
  return a == null ? -1 : a.indexOf(b, i);
}

static int indexOf(String a, int i, String b) {
  return a == null || b == null ? -1 : a.indexOf(b, i);
}

static <A> int indexOf(A[] x, A a) {
  if (x == null) return -1;
  for (int i = 0; i < l(x); i++)
    if (eq(x[i], a))
      return i;
  return -1;
}
static boolean contains(Collection c, Object o) {
  return c != null && c.contains(o);
}

static boolean contains(Object[] x, Object o) {
  if (x != null)
    for (Object a : x)
      if (eq(a, o))
        return true;
  return false;
}

static boolean contains(String s, char c) {
  return s != null && s.indexOf(c) >= 0;
}

static boolean contains(String s, String b) {
  return s != null && s.indexOf(b) >= 0;
}
static <A> void remove(List<A> l, int i) {
  if (l != null && i >= 0 && i < l(l))
    l.remove(i);
}

static <A> void remove(Collection<A> l, A a) {
  if (l != null) l.remove(a);
}
// get purpose 1: access a list/array/map (safer version of x.get(y))

static <A> A get(List<A> l, int idx) {
  return l != null && idx >= 0 && idx < l(l) ? l.get(idx) : null;
}

// seems to conflict with other signatures
/*static <A, B> B get(Map<A, B> map, A key) {
  ret map != null ? map.get(key) : null;
}*/

static <A> A get(A[] l, int idx) {
  return idx >= 0 && idx < l(l) ? l[idx] : null;
}

// default to false
static boolean get(boolean[] l, int idx) {
  return idx >= 0 && idx < l(l) ? l[idx] : false;
}

// get purpose 2: access a field by reflection or a map

static Object get(Object o, String field) {
  try {
    if (o instanceof Class) return get((Class) o, field);
    
    if (o instanceof Map)
      return ((Map) o).get(field);
      
    Field f = getOpt_findField(o.getClass(), field);
    if (f != null) {
      f.setAccessible(true);
      return f.get(o);
    }
      
    
  } catch (Exception e) {
    throw asRuntimeException(e);
  }
  throw new RuntimeException("Field '" + field + "' not found in " + o.getClass().getName());
}

static Object get_raw(Object o, String field) {
  try {
    Field f = get_findField(o.getClass(), field);
    f.setAccessible(true);
    return f.get(o);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static Object get(Class c, String field) {
  try {
    Field f = get_findStaticField(c, field);
    f.setAccessible(true);
    return f.get(null);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static Field get_findStaticField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field) && (f.getModifiers() & java.lang.reflect.Modifier.STATIC) != 0)
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  throw new RuntimeException("Static field '" + field + "' not found in " + c.getName());
}

static Field get_findField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field))
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  throw new RuntimeException("Field '" + field + "' not found in " + c.getName());
}

static <A> List<A> subList(List<A> l, int startIndex) {
  return subList(l, startIndex, l(l));
}

static <A> List<A> subList(List<A> l, int startIndex, int endIndex) {
  startIndex = max(0, min(l(l), startIndex));
  endIndex = max(0, min(l(l), endIndex));
  if (startIndex > endIndex) return litlist();
  return l.subList(startIndex, endIndex);
}


static void set(Object o, String field, Object value) {
  if (o instanceof Class) set((Class) o, field, value);
  else try {
    Field f = set_findField(o.getClass(), field);
    smartSet(f, o, value);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static void set(Class c, String field, Object value) {
  try {
    Field f = set_findStaticField(c, field);
    smartSet(f, null, value);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}
  
static Field set_findStaticField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field) && (f.getModifiers() & java.lang.reflect.Modifier.STATIC) != 0)
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  throw new RuntimeException("Static field '" + field + "' not found in " + c.getName());
}

static Field set_findField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field))
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  throw new RuntimeException("Field '" + field + "' not found in " + c.getName());
}
static <A> void addAll(Collection<A> c, Collection<A> b) {
  if (c != null && b != null) c.addAll(b);
}

static <A> void addAll(Collection<A> c, A... b) {
  if (c != null) c.addAll(Arrays.asList(b));
}
// optimistic signature that usually holds
static <A> A clone(A o) {
  ArrayDeque<Runnable> q = new ArrayDeque();
  Object x = clone_impl(o, new IdentityHashMap(), q);
  while (!q.isEmpty())
    q.poll().run();
  return (A) x;
}

static Object clone_impl(Object o, final IdentityHashMap seen, final ArrayDeque<Runnable> q) { try {
  if (o == null) return null;
    
  Object y = seen.get(o);
  if (y != null) return y;
  
  if (o instanceof List) {
    //print("Cloning list: " + o);
    final List l = new ArrayList();
    seen.put(o, l);
    for (final Object x : (List) o)
      q.add(new Runnable() { public void run() { try {  l.add(clone_impl(x, seen, q)) ;
} catch (Exception __e) { throw rethrow(__e); } }  public String toString() { return "l.add(clone_impl(x, seen, q))"; }});
    return l;
  }
  
  if (o instanceof Map) {
    final Map m = similarEmptyMap((Map) o);
    seen.put(o, m);
    for (Object entry : ((Map) o).entrySet()) {
      final Map.Entry e = (Map.Entry) entry;
      q.add(new Runnable() { public void run() { try { 
        m.put(clone_impl(e.getKey(), seen, q), clone_impl(e.getValue(), seen, q))
      ;
} catch (Exception __e) { throw rethrow(__e); } }  public String toString() { return "m.put(clone_impl(e.getKey(), seen, q), clone_impl(e.getValue(), seen, q))"; }});
    }
    return m;
  }
  
  if (o instanceof String || o instanceof Number || o instanceof Boolean) return o;
    
  if (o instanceof Object[]) {
    final Object[] l = (Object[]) o;
    final Object[] l2 = l.clone();
    seen.put(o, l2);
    for (int i = 0; i < l.length; i++) {
      final int _i = i;
      q.add(new Runnable() { public void run() { try {  l2[_i] = clone_impl(l[_i], seen, q) ;
} catch (Exception __e) { throw rethrow(__e); } }  public String toString() { return "l2[_i] = clone_impl(l[_i], seen, q)"; }});
    }
    return l2;
  }
  
  // clone an arbitrary custom object

  //print("Cloning custom: " + o);
  final Object clone = nuObjectWithoutArguments(o.getClass());
  seen.put(o, clone);
  Class c = o.getClass();
  while (c != Object.class) {
    Field[] fields = c.getDeclaredFields();
    for (final Field field : fields) {
      if ((field.getModifiers() & Modifier.STATIC) != 0)
        continue;
      field.setAccessible(true);
      final Object value = field.get(o);
      q.add(new Runnable() { public void run() { try {  field.set(clone, clone_impl(value, seen, q)) ;
} catch (Exception __e) { throw rethrow(__e); } }  public String toString() { return "field.set(clone, clone_impl(value, seen, q))"; }});
    }
    c = c.getSuperclass();
  }
  return clone;
} catch (Exception __e) { throw rethrow(__e); } }



static Iterator emptyIterator() {
  return Collections.emptyIterator();
}
static Map similarEmptyMap(Map m) {
  if (m instanceof TreeMap) return new TreeMap();
  if (m instanceof LinkedHashMap) return new LinkedHashMap();
  
  // default to a hash map
  return new HashMap();
}
static int min(int a, int b) {
  return Math.min(a, b);
}

static long min(long a, long b) {
  return Math.min(a, b);
}

static float min(float a, float b) { return Math.min(a, b); }
static float min(float a, float b, float c) { return min(min(a, b), c); }

static double min(double a, double b) {
  return Math.min(a, b);
}

static double min(double[] c) {
  double x = Double.MAX_VALUE;
  for (double d : c) x = Math.min(x, d);
  return x;
}

static float min(float[] c) {
  float x = Float.MAX_VALUE;
  for (float d : c) x = Math.min(x, d);
  return x;
}

static byte min(byte[] c) {
  byte x = 127;
  for (byte d : c) if (d < x) x = d;
  return x;
}

static short min(short[] c) {
  short x = 0x7FFF;
  for (short d : c) if (d < x) x = d;
  return x;
}
static <A> ArrayList<A> litlist(A... a) {
  ArrayList l = new ArrayList(a.length);
  for (A x : a) l.add(x);
  return l;
}
static int max(int a, int b) { return Math.max(a, b); }
static int max(int a, int b, int c) { return max(max(a, b), c); }
static long max(int a, long b) { return Math.max((long) a, b); }
static long max(long a, long b) { return Math.max(a, b); }
static double max(int a, double b) { return Math.max((double) a, b); }
static float max(float a, float b) { return Math.max(a, b); }
static double max(double a, double b) { return Math.max(a, b); }

static int max(Collection<Integer> c) {
  int x = Integer.MIN_VALUE;
  for (int i : c) x = max(x, i);
  return x;
}

static double max(double[] c) {
  if (c.length == 0) return Double.MIN_VALUE;
  double x = c[0];
  for (int i = 1; i < c.length; i++) x = Math.max(x, c[i]);
  return x;
}

static float max(float[] c) {
  if (c.length == 0) return Float.MAX_VALUE;
  float x = c[0];
  for (int i = 1; i < c.length; i++) x = Math.max(x, c[i]);
  return x;
}

static byte max(byte[] c) {
  byte x = -128;
  for (byte d : c) if (d > x) x = d;
  return x;
}

static short max(short[] c) {
  short x = -0x8000;
  for (short d : c) if (d > x) x = d;
  return x;
}
static void smartSet(Field f, Object o, Object value) throws Exception {
  f.setAccessible(true);
  
  // take care of common case (long to int)
  if (f.getType() == int.class && value instanceof Long)
    value = ((Long) value).intValue();
    
  try {
    f.set(o, value);
  } catch (Exception e) {
    
    throw e;
  }
}
static Map<Class, Constructor> nuObjectWithoutArguments_cache = newWeakHashMap();

static Object nuObjectWithoutArguments(String className) { try {
  return nuObjectWithoutArguments(classForName(className));
} catch (Exception __e) { throw rethrow(__e); } }

static <A> A nuObjectWithoutArguments(Class<A> c) { try {
  Constructor m;
  m = nuObjectWithoutArguments_cache.get(c);
  if (m == null)
    nuObjectWithoutArguments_cache.put(c, m = nuObjectWithoutArguments_findConstructor(c));
  return (A) m.newInstance();
} catch (Exception __e) { throw rethrow(__e); } }

static Constructor nuObjectWithoutArguments_findConstructor(Class c) {
  for (Constructor m : c.getDeclaredConstructors())
    if (empty(m.getParameterTypes())) {
      m.setAccessible(true);
      return m;
    }
  throw fail("No default constructor found in " + c.getName());
}

static Field getOpt_findField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field))
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  return null;
}


static boolean empty(Collection c) { return c == null || c.isEmpty(); }
static boolean empty(String s) { return s == null || s.length() == 0; }
static boolean empty(Map map) { return map == null || map.isEmpty(); }
static boolean empty(Object[] o) { return o == null || o.length == 0; }
static boolean empty(Object o) {
  if (o instanceof Collection) return empty((Collection) o);
  if (o instanceof String) return empty((String) o);
  if (o instanceof Map) return empty((Map) o);
  if (o instanceof Object[]) return empty((Object[]) o);
  if (o == null) return true;
  throw fail("unknown type for 'empty': " + getType(o));
}

static boolean empty(float[] a) { return a == null || a.length == 0; }
static boolean empty(int[] a) { return a == null || a.length == 0; }
static boolean empty(long[] a) { return a == null || a.length == 0; }
static Map<String, Class> classForName_cache = synchroHashMap();

static Class classForName(String name) { try {
  Class c = classForName_cache.get(name);
  if (c == null)
    classForName_cache.put(name, c = Class.forName(name));
  return c;
} catch (Exception __e) { throw rethrow(__e); } }


static String getType(Object o) {
  return getClassName(o);
}

}