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 {
static int n = 1000000;

// iterate safely (& quickly) in the face of concurrent modifications
static <A, B> IterableIterator<A> iterateKeysQuickly(final NavigableMap<A, B> map) {
  return iteratorFromFunction(new F0<A>() {
    Iterator<A> it = keys(map).iterator();
    A key;
    
    A get() {
      synchronized(map) {
        try {
          if (!it.hasNext()) return null;
          return key = it.next();
        } catch (ConcurrentModificationException e) {
          print("Re-iterating");
          it = map.tailMap(key, false).keySet().iterator();
          if (!it.hasNext()) return null;
          return key = it.next(); // Can't throw another exception
        }
      }
    }
  });
}

public static void main(final String[] args) throws Exception {
  final NavigableMap<String, Boolean> map = synchroNavigableMap(litcimap());
  final List<String> ids = new ArrayList();
  for (int _repeat_0 = 0; _repeat_0 < n; _repeat_0++)  {
    map.put(addAndReturn(ids, randomID()), Boolean.TRUE);
  }
  
  for (int _repeat_1 = 0; _repeat_1 < 5; _repeat_1++)  {
    int i = 0;
    long sum = 0;
    long _startTime_2 = sysNow(); 
      for (String key : keys(map)) {
        if (!key.startsWith("_")) {
          ++i;
          sum += key.hashCode();
        }
      }
     done2_always("Iterating", _startTime_2); 
    assertEquals(i, n);

    i = 0;
    long sum2 = 0;
    long _startTime_3 = sysNow(); 
      for (String key : iterateKeysQuickly(map)) {
        if (!key.startsWith("_")) {
          ++i;
          sum2 += key.hashCode();
        }
      }
     done2_always("Iterating quickly", _startTime_3); 
    assertEquals(i, n);
    assertEquals(sum, sum2);
  }
}
static <A, B> Set<A> keys(Map<A, B> map) {
  return map == null ? new HashSet() : map.keySet();
}

static Set keys(Object map) {
  return keys((Map) map);
}




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 long done2_always(long startTime, String desc) {
  long time = sysNow()-startTime;
  print(desc + " [" + time + " ms]");
  return time;
}

static long done2_always(String desc, long startTime) {
  return done2_always(startTime, desc);
}

static long done2_always(long startTime) {
  return done2_always(startTime, "");
}
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 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 int randomID_defaultLength = 12;

static String randomID(int length) {
  return makeRandomID(length);
}

static String randomID() {
  return randomID(randomID_defaultLength);
}
static long sysNow() {
  return System.nanoTime()/1000000;
}
static RuntimeException asRuntimeException(Throwable t) {
  if (t instanceof Error)
    _handleError((Error) t);
  return t instanceof RuntimeException ? (RuntimeException) t : new RuntimeException(t);
}
static <A, B> NavigableMap<A, B> synchroNavigableMap(NavigableMap<A, B> map) {
  return Collections.synchronizedNavigableMap(map);
}
// 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());
}

// f: func -> A (stream ends when f returns null)
static <A> IterableIterator<A> iteratorFromFunction(final Object f) {
  class IFF extends IterableIterator<A> {
    A a;
    boolean done;
    
    public boolean hasNext() {
      getNext();
      return !done;
    }
    
    public A next() {
      getNext();
      if (done) throw fail();
      A _a = a;
      a = null;
      return _a;
    }
    
    void getNext() {
      if (done || a != null) return;
      a = (A) callF(f);
      done = a == null;
    }
  };
  return new IFF();
}

// optimized version for F0 argument
static <A> IterableIterator<A> iteratorFromFunction(final F0<A> f) {
  class IFF2 extends IterableIterator<A> {
    A a;
    boolean done;
    
    public boolean hasNext() {
      getNext();
      return !done;
    }
    
    public A next() {
      getNext();
      if (done) throw fail();
      A _a = a;
      a = null;
      return _a;
    }
    
    void getNext() {
      if (done || a != null) return;
      a = f.get();
      done = a == null;
    }
  };
  return new IFF2();
}
static TreeMap litcimap(Object... x) {
  return litCIMap(x);
}
static <B, A extends B> A addAndReturn(Collection<B> c, A a) {
  if (c != null) c.add(a);
  return a;
}


static String fixNewLines(String s) {
  return s.replace("\r\n", "\n").replace("\r", "\n");
}
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 WeakHashMap<Class, ArrayList<Method>> callF_cache = new WeakHashMap();


  static <A> A callF(F0<A> f) {
    return f == null ? null : f.get();
  }



  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 <A, B> Map<A, B> newWeakHashMap() {
  return _registerWeakMap(synchroMap(new WeakHashMap()));
}
static String makeRandomID(int length) {
  Random random = new Random();
  char[] id = new char[length];
  for (int i = 0; i < id.length; i++)
    id[i] = (char) ((int) 'a' + random.nextInt(26));
  return new String(id);
}
static boolean isFalse(Object o) {
  return eq(false, o);
}
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 TreeMap litCIMap(Object... x) {
  TreeMap map = caseInsensitiveMap();
  litmap_impl(map, x);
  return map;
}
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 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 Map synchroMap() {
  return synchroHashMap();
}

static <A, B> Map<A, B> synchroMap(Map<A, B> map) {
  return Collections.synchronizedMap(map);
}
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 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 <A> TreeMap<String, A> caseInsensitiveMap() {
  return new TreeMap(String.CASE_INSENSITIVE_ORDER);
}
static RuntimeException rethrow(Throwable e) {
  throw asRuntimeException(e);
}
static Thread currentThread() {
  return Thread.currentThread();
}
static boolean eq(Object a, Object b) {
  return a == null ? b == null : a == b || a.equals(b);
}
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 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 String getClassName(Object o) {
  return o == null ? "null" : o instanceof Class ? ((Class) o).getName() : o.getClass().getName();
}
static Map litmap(Object... x) {
  HashMap map = new HashMap();
  litmap_impl(map, x);
  return map;
}

static void litmap_impl(Map map, Object... x) {
  for (int i = 0; i < x.length-1; i += 2)
    if (x[i+1] != null)
      map.put(x[i], x[i+1]);
}


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 Object callFunction(Object f, Object... args) {
  return callF(f, args);
}
static List<String> classNames(Collection l) {
  return getClassNames(l);
}

static List<String> classNames(Object[] l) {
  return getClassNames(Arrays.asList(l));
}
static Class javax() {
  return getJavaX();
}
static Class mc() {
  return main.class;
}
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, 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 String getStackTrace2(Throwable throwable) {
  return hideCredentials(getStackTrace(throwable) + replacePrefix("java.lang.RuntimeException: ", "FAIL: ",
    hideCredentials(str(getInnerException(throwable)))) + "\n");
}
// 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 void printException(Throwable e) {
  printStackTrace(e);
}
static <A> List<A> synchroList() {
  return Collections.synchronizedList(new ArrayList<A>());
}

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

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 String getStackTrace(Throwable throwable) {
  lastException(throwable);
  StringWriter writer = new StringWriter();
  throwable.printStackTrace(new PrintWriter(writer));
  return hideCredentials(writer.toString());
}
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 String str(Object o) {
  return o == null ? "null" : o.toString();
}

static String str(char[] c) {
  return new String(c);
}
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>");
}
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 Class __javax;

static Class getJavaX() {
  return __javax;
}
static Throwable getInnerException(Throwable e) {
  while (e.getCause() != null)
    e = e.getCause();
  return e;
}


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 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 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 boolean neq(Object a, Object b) {
  return !eq(a, b);
}
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 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 abstract class F0<A> {
  abstract A get();
}static abstract class F1<A, B> {
  abstract B get(A a);
}// you still need to implement hasNext() and next()
static abstract class IterableIterator<A> implements Iterator<A>, Iterable<A> {
  public Iterator<A> iterator() {
    return this;
  }
  
  public void remove() {
    unsupportedOperation();
  }
}

static <A> Iterator<A> iterator(Collection<A> c) {
  return c == null ? emptyIterator() : c.iterator();
}
static UnsupportedOperationException unsupportedOperation() {
  throw new UnsupportedOperationException();
}


static Iterator emptyIterator() {
  return Collections.emptyIterator();
}

}