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 {
    print("hello");
  }

  public static volatile StringBuffer local_log = new StringBuffer();

  public static volatile Appendable print_log = local_log;

  public static volatile int print_log_max = 1024 * 1024;

  public static volatile int local_log_max = 100 * 1024;

  public static boolean print_silent;

  public static Object print_byThread_lock = new Object();

  public static volatile ThreadLocal<Object> print_byThread;

  public static volatile Object print_allThreads;

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

  public static <A> A print(String s, A o) {
    print((endsWithLetterOrDigit(s) ? s + ": " : s) + o);
    return o;
  }

  public static <A> A print(A o) {
    ping_okInCleanUp();
    if (print_silent)
      return o;
    String s = String.valueOf(o) + "\n";
    print_noNewLine(s);
    return o;
  }

  public static void print_noNewLine(String s) {
    Object f = print_byThread == null ? null : print_byThread.get();
    if (f == null)
      f = print_allThreads;
    if (f != null)
      if (isFalse(callF(f, s)))
        return;
    print_raw(s);
  }

  public static void print_raw(String s) {
    s = fixNewLines(s);
    Appendable loc = local_log;
    Appendable 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);
  }

  public static boolean endsWithLetterOrDigit(String s) {
    return s != null && s.length() > 0 && Character.isLetterOrDigit(s.charAt(s.length() - 1));
  }

  public static void ping_okInCleanUp() {
    if (ping_pauseAll || ping_anyActions)
      ping_impl(true);
  }

  public static boolean isFalse(Object o) {
    return eq(false, o);
  }

  public static Map<Class, ArrayList<Method>> callF_cache = newDangerousWeakHashMap();

  public static <A> void callF(VF1<A> f, A a) {
    if (f != null)
      f.get(a);
  }

  public 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 invokeMethod(methods.get(0), f, args);
      for (int i = 0; i < n; i++) {
        Method m = methods.get(i);
        if (call_checkArgs(m, args, false))
          return invokeMethod(m, f, args);
      }
      throw fail("No matching get method in " + getClassName(c));
    } catch (Exception __e) {
      throw rethrow(__e);
    }
  }

  public 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;
  }

  public static String fixNewLines(String s) {
    int i = indexOf(s, '\r');
    if (i < 0)
      return s;
    int l = s.length();
    StringBuilder out = new StringBuilder(l);
    out.append(s, 0, i);
    for (; i < l; i++) {
      char c = s.charAt(i);
      if (c != '\r')
        out.append(c);
      else {
        out.append('\n');
        if (i + 1 < l && s.charAt(i + 1) == '\n')
          ++i;
      }
    }
    return out.toString();
  }

  public static void print_append(Appendable _buf, String s, int max) {
    try {
      synchronized (_buf) {
        _buf.append(s);
        if (!(_buf instanceof StringBuilder))
          return;
        StringBuilder buf = (StringBuilder) (_buf);
        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);
          }
      }
    } catch (Exception __e) {
      throw rethrow(__e);
    }
  }

  public static volatile boolean ping_pauseAll;

  public static int ping_sleep = 100;

  public static volatile boolean ping_anyActions;

  public static Map<Thread, Object> ping_actions = newWeakHashMap();

  public static ThreadLocal<Boolean> ping_isCleanUpThread = new ThreadLocal();

  public static boolean ping() {
    if (ping_pauseAll || ping_anyActions)
      ping_impl(true);
    return true;
  }

  public static boolean ping_impl(boolean okInCleanUp) {
    try {
      if (ping_pauseAll && !isAWTThread()) {
        do Thread.sleep(ping_sleep); while (ping_pauseAll);
        return true;
      }
      if (ping_anyActions) {
        if (!okInCleanUp && !isTrue(ping_isCleanUpThread.get()))
          failIfUnlicensed();
        Object action = null;
        synchronized (ping_actions) {
          if (!ping_actions.isEmpty()) {
            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);
    }
  }

  public static boolean eq(Object a, Object b) {
    return a == null ? b == null : a == b || b != null && a.equals(b);
  }

  public static <A, B> Map<A, B> newDangerousWeakHashMap() {
    return _registerDangerousWeakMap(synchroMap(new WeakHashMap()));
  }

  public static <A, B> Map<A, B> newDangerousWeakHashMap(Object initFunction) {
    return _registerDangerousWeakMap(synchroMap(new WeakHashMap()), initFunction);
  }

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

  public static String callMC_key;

  public static Method callMC_value;

  public static Object callMC(String method, String[] arg) {
    return callMC(method, new Object[] { arg });
  }

  public static Object callMC(String method, Object... args) {
    try {
      Method me;
      if (callMC_cache == null)
        callMC_cache = new HashMap();
      synchronized (callMC_cache) {
        me = method == callMC_key ? callMC_value : null;
      }
      if (me != null)
        try {
          return invokeMethod(me, 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 invokeMethod(me, 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 invokeMethod(me, null, args);
      }
      throw fail("No method called " + method + " with matching arguments found in main");
    } catch (Exception __e) {
      throw rethrow(__e);
    }
  }

  public 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();
      }
    }
  }

  public static int l(Object[] a) {
    return a == null ? 0 : a.length;
  }

  public static int l(boolean[] a) {
    return a == null ? 0 : a.length;
  }

  public static int l(byte[] a) {
    return a == null ? 0 : a.length;
  }

  public static int l(short[] a) {
    return a == null ? 0 : a.length;
  }

  public static int l(long[] a) {
    return a == null ? 0 : a.length;
  }

  public static int l(int[] a) {
    return a == null ? 0 : a.length;
  }

  public static int l(float[] a) {
    return a == null ? 0 : a.length;
  }

  public static int l(double[] a) {
    return a == null ? 0 : a.length;
  }

  public static int l(char[] a) {
    return a == null ? 0 : a.length;
  }

  public static int l(Collection c) {
    return c == null ? 0 : c.size();
  }

  public static int l(Map m) {
    return m == null ? 0 : m.size();
  }

  public static int l(CharSequence s) {
    return s == null ? 0 : s.length();
  }

  public static long l(File f) {
    return f == null ? 0 : f.length();
  }

  public static int l(Object o) {
    return o == null ? 0 : o instanceof String ? l((String) o) : o instanceof Map ? l((Map) o) : o instanceof Collection ? l((Collection) o) : o instanceof Object[] ? l((Object[]) o) : o instanceof boolean[] ? l((boolean[]) o) : o instanceof byte[] ? l((byte[]) o) : o instanceof char[] ? l((char[]) o) : o instanceof short[] ? l((short[]) o) : o instanceof int[] ? l((int[]) o) : o instanceof float[] ? l((float[]) o) : o instanceof double[] ? l((double[]) o) : o instanceof long[] ? l((long[]) o) : (Integer) call(o, "size");
  }

  public static RuntimeException fail() {
    throw new RuntimeException("fail");
  }

  public static RuntimeException fail(Throwable e) {
    throw asRuntimeException(e);
  }

  public static RuntimeException fail(Object msg) {
    throw new RuntimeException(String.valueOf(msg));
  }

  public static RuntimeException fail(String msg) {
    throw new RuntimeException(msg == null ? "" : msg);
  }

  public static RuntimeException fail(String msg, Throwable innerException) {
    throw new RuntimeException(msg, innerException);
  }

  public static String getClassName(Object o) {
    return o == null ? "null" : o instanceof Class ? ((Class) o).getName() : o.getClass().getName();
  }

  public static Object invokeMethod(Method m, Object o, Object... args) {
    try {
      try {
        return m.invoke(o, args);
      } catch (InvocationTargetException e) {
        throw rethrow(getExceptionCause(e));
      } catch (IllegalArgumentException e) {
        throw new IllegalArgumentException(e.getMessage() + " - was calling: " + m + ", args: " + joinWithSpace(classNames(args)));
      }
    } catch (Exception __e) {
      throw rethrow(__e);
    }
  }

  public 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;
  }

  public static RuntimeException rethrow(Throwable t) {
    if (t instanceof Error)
      _handleError((Error) t);
    throw t instanceof RuntimeException ? (RuntimeException) t : new RuntimeException(t);
  }

  public 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;
  }

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

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

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

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

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

  public static int indexOf(String a, int i, char b) {
    return indexOf(a, b, i);
  }

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

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

  public 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;
  }

  public static <A, B> Map<A, B> newWeakHashMap() {
    return _registerWeakMap(synchroMap(new WeakHashMap()));
  }

  public static boolean isAWTThread() {
    if (isAndroid())
      return false;
    if (isHeadless())
      return false;
    return isAWTThread_awt();
  }

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

  public static boolean isTrue(Object o) {
    if (o instanceof Boolean)
      return ((Boolean) o).booleanValue();
    if (o == null)
      return false;
    if (o instanceof ThreadLocal)
      return isTrue(((ThreadLocal) o).get());
    throw fail(getClassName(o));
  }

  public static void failIfUnlicensed() {
    assertTrue("license off", licensed());
  }

  public static Thread currentThread() {
    return Thread.currentThread();
  }

  public static String str(Object o) {
    return o == null ? "null" : o.toString();
  }

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

  public static List<Pair> _registerDangerousWeakMap_preList;

  public static <A> A _registerDangerousWeakMap(A map) {
    return _registerDangerousWeakMap(map, null);
  }

  public static <A> A _registerDangerousWeakMap(A map, Object init) {
    callF(init, map);
    if (init instanceof String) {
      final String f = (String) (init);
      init = new VF1<Map>() {

        public void get(Map map) {
          try {
            callMC(f, map);
          } catch (Exception __e) {
            throw rethrow(__e);
          }
        }

        public String toString() {
          return "callMC(f, map)";
        }
      };
    }
    if (javax() == null) {
      if (_registerDangerousWeakMap_preList == null)
        _registerDangerousWeakMap_preList = synchroList();
      _registerDangerousWeakMap_preList.add(pair(map, init));
      return map;
    }
    call(javax(), "_registerDangerousWeakMap", map, init);
    return map;
  }

  public static void _onLoad_registerDangerousWeakMap() {
    assertNotNull(javax());
    if (_registerDangerousWeakMap_preList == null)
      return;
    for (Pair p : _registerDangerousWeakMap_preList) _registerDangerousWeakMap(p.a, p.b);
    _registerDangerousWeakMap_preList = null;
  }

  public static Map synchroMap() {
    return synchroHashMap();
  }

  public static <A, B> Map<A, B> synchroMap(Map<A, B> map) {
    return Collections.synchronizedMap(map);
  }

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

  public static List<String> classNames(Object[] l) {
    return getClassNames(Arrays.asList(l));
  }

  public static Class mc() {
    return main.class;
  }

  public 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);
  }

  public static <A> A call(Object o) {
    return (A) callF(o);
  }

  public static <A> A call(Object o, String method, String[] arg) {
    return call(o, method, new Object[] { arg });
  }

  public static <A> A call(Object o, String method, Object... args) {
    return (A) call_cached(o, method, args);
  }

  public static RuntimeException asRuntimeException(Throwable t) {
    if (t instanceof Error)
      _handleError((Error) t);
    return t instanceof RuntimeException ? (RuntimeException) t : new RuntimeException(t);
  }

  public static Throwable getExceptionCause(Throwable e) {
    Throwable c = e.getCause();
    return c != null ? c : e;
  }

  public static String joinWithSpace(Collection<String> c) {
    return join(" ", c);
  }

  public static String joinWithSpace(String... c) {
    return join(" ", c);
  }

  public 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);
  }

  public static void _handleError(Error e) {
    call(javax(), "_handleError", e);
  }

  public static List _registerWeakMap_preList;

  public static <A> A _registerWeakMap(A map) {
    if (javax() == null) {
      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;
  }

  public static void _onLoad_registerWeakMap() {
    assertNotNull(javax());
    if (_registerWeakMap_preList == null)
      return;
    for (Object o : _registerWeakMap_preList) _registerWeakMap(o);
    _registerWeakMap_preList = null;
  }

  public static int isAndroid_flag;

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

  public static Boolean isHeadless_cache;

  public static boolean isHeadless() {
    if (isHeadless_cache != null)
      return isHeadless_cache;
    if (isAndroid())
      return isHeadless_cache = true;
    if (GraphicsEnvironment.isHeadless())
      return isHeadless_cache = true;
    try {
      SwingUtilities.isEventDispatchThread();
      return isHeadless_cache = false;
    } catch (Throwable e) {
      return isHeadless_cache = true;
    }
  }

  public static void assertTrue(Object o) {
    if (!(eq(o, true)))
      throw fail(str(o));
  }

  public static boolean assertTrue(String msg, boolean b) {
    if (!b)
      throw fail(msg);
    return b;
  }

  public static boolean assertTrue(boolean b) {
    if (!b)
      throw fail("oops");
    return b;
  }

  public static volatile boolean licensed_yes = true;

  public static boolean licensed() {
    if (!licensed_yes)
      return false;
    ping_okInCleanUp();
    return true;
  }

  public static void licensed_off() {
    licensed_yes = false;
  }

  public static Class javax() {
    return getJavaX();
  }

  public static <A> List<A> synchroList() {
    return Collections.synchronizedList(new ArrayList<A>());
  }

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

  public static <A, B> Pair<A, B> pair(A a, B b) {
    return new Pair(a, b);
  }

  public static <A> Pair<A, A> pair(A a) {
    return new Pair(a, a);
  }

  public static <A> A assertNotNull(A a) {
    assertTrue(a != null);
    return a;
  }

  public static <A> A assertNotNull(String msg, A a) {
    assertTrue(msg, a != null);
    return a;
  }

  public static Map synchroHashMap() {
    return Collections.synchronizedMap(new HashMap());
  }

  public 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;
  }

  public static Object call_cached(Object o, String method, Object... args) {
    try {
      if (o == null)
        return null;
      if (o instanceof Class) {
        Class c = (Class) o;
        _MethodCache cache = callOpt_getCache(c);
        Method me = cache.findMethod(method, args);
        if (me == null)
          throw fail("Method " + c.getName() + "." + method + "(" + joinWithComma(classNames(args)) + ") not found");
        if ((me.getModifiers() & Modifier.STATIC) == 0)
          throw fail("Method " + c.getName() + "." + method + "(" + joinWithComma(classNames(args)) + ") not static");
        return invokeMethod(me, null, args);
      } else {
        Class c = o.getClass();
        _MethodCache cache = callOpt_getCache(c);
        Method me = cache.findMethod(method, args);
        if (me == null)
          throw fail("Method " + c.getName() + "." + method + "(" + joinWithComma(classNames(args)) + ") not found");
        return invokeMethod(me, o, args);
      }
    } catch (Exception __e) {
      throw rethrow(__e);
    }
  }

  public static <A> String join(String glue, Iterable<A> strings) {
    if (strings == null)
      return "";
    StringBuilder buf = new StringBuilder();
    Iterator<A> i = strings.iterator();
    if (i.hasNext()) {
      buf.append(i.next());
      while (i.hasNext()) buf.append(glue).append(i.next());
    }
    return buf.toString();
  }

  public static String join(String glue, String... strings) {
    return join(glue, Arrays.asList(strings));
  }

  public static <A> String join(Iterable<A> strings) {
    return join("", strings);
  }

  public static <A> String join(Iterable<A> strings, String glue) {
    return join(glue, strings);
  }

  public static String join(String[] strings) {
    return join("", strings);
  }

  public static String join(String glue, Pair p) {
    return p == null ? "" : str(p.a) + glue + str(p.b);
  }

  public static final Map<Class, _MethodCache> callOpt_cache = newDangerousWeakHashMap();

  public static Object callOpt_cached(Object o, String methodName, Object... args) {
    try {
      if (o == null)
        return null;
      if (o instanceof Class) {
        Class c = (Class) o;
        _MethodCache cache = callOpt_getCache(c);
        Method me = cache.findMethod(methodName, args);
        if (me == null || (me.getModifiers() & Modifier.STATIC) == 0)
          return null;
        return invokeMethod(me, null, args);
      } else {
        Class c = o.getClass();
        _MethodCache cache = callOpt_getCache(c);
        Method me = cache.findMethod(methodName, args);
        if (me == null)
          return null;
        return invokeMethod(me, o, args);
      }
    } catch (Exception __e) {
      throw rethrow(__e);
    }
  }

  public static _MethodCache callOpt_getCache(Class c) {
    synchronized (callOpt_cache) {
      _MethodCache cache = callOpt_cache.get(c);
      if (cache == null)
        callOpt_cache.put(c, cache = new _MethodCache(c));
      return cache;
    }
  }

  public static void printException(Throwable e) {
    printStackTrace(e);
  }

  public static Class __javax;

  public static Class getJavaX() {
    try {
      return __javax;
    } catch (Exception __e) {
      throw rethrow(__e);
    }
  }

  public static String joinWithComma(Collection<String> c) {
    return join(", ", c);
  }

  public static String joinWithComma(String... c) {
    return join(", ", c);
  }

  public static String joinWithComma(Pair p) {
    return p == null ? "" : joinWithComma(str(p.a), str(p.b));
  }

  public static Throwable printStackTrace(Throwable e) {
    print(getStackTrace(e));
    return e;
  }

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

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

  public static String getStackTrace(Throwable throwable) {
    lastException(throwable);
    return getStackTrace_noRecord(throwable);
  }

  public static String getStackTrace_noRecord(Throwable throwable) {
    StringWriter writer = new StringWriter();
    throwable.printStackTrace(new PrintWriter(writer));
    return hideCredentials(writer.toString());
  }

  public static String getStackTrace() {
    return getStackTrace_noRecord(new Throwable());
  }

  public static volatile PersistableThrowable lastException_lastException;

  public static PersistableThrowable lastException() {
    return lastException_lastException;
  }

  public static void lastException(Throwable e) {
    lastException_lastException = persistableThrowable(e);
  }

  public static String hideCredentials(URL url) {
    return url == null ? null : hideCredentials(str(url));
  }

  public static String hideCredentials(String url) {
    return url.replaceAll("([&?])(_pass|key)=[^&\\s\"]*", "$1$2=<hidden>");
  }

  public static String hideCredentials(Object o) {
    return hideCredentials(str(o));
  }

  public static PersistableThrowable persistableThrowable(Throwable e) {
    return e == null ? null : new PersistableThrowable(e);
  }

  public static final class _MethodCache {

    public final Class c;

    public final HashMap<String, List<Method>> cache = new HashMap();

    public _MethodCache(Class c) {
      this.c = c;
      _init();
    }

    public void _init() {
      Class _c = c;
      while (_c != null) {
        for (Method m : _c.getDeclaredMethods()) {
          m.setAccessible(true);
          multiMapPut(cache, m.getName(), m);
        }
        _c = _c.getSuperclass();
      }
    }

    public Method findMethod(String method, Object[] args) {
      try {
        List<Method> m = cache.get(method);
        if (m == null)
          return null;
        int n = m.size();
        for (int i = 0; i < n; i++) {
          Method me = m.get(i);
          if (call_checkArgs(me, args, false))
            return me;
        }
        return null;
      } catch (Exception __e) {
        throw rethrow(__e);
      }
    }
  }

  public abstract static class VF1<A> {

    public abstract void get(A a);
  }

  public static class PersistableThrowable {

    public String className;

    public String msg;

    public String stacktrace;

    public PersistableThrowable() {
    }

    public PersistableThrowable(Throwable e) {
      if (e == null)
        className = "Crazy Null Error";
      else {
        className = getClassName(e).replace('/', '.');
        msg = e.getMessage();
        stacktrace = getStackTrace_noRecord(e);
      }
    }

    public String toString() {
      return nempty(msg) ? className + ": " + msg : className;
    }
  }

  public static class Pair<A, B> implements Comparable<Pair<A, B>> {

    public A a;

    public B b;

    public Pair() {
    }

    public Pair(A a, B b) {
      this.b = b;
      this.a = a;
    }

    public int hashCode() {
      return hashCodeFor(a) + 2 * hashCodeFor(b);
    }

    public boolean equals(Object o) {
      if (o == this)
        return true;
      if (!(o instanceof Pair))
        return false;
      Pair t = (Pair) o;
      return eq(a, t.a) && eq(b, t.b);
    }

    public String toString() {
      return "<" + a + ", " + b + ">";
    }

    public int compareTo(Pair<A, B> p) {
      if (p == null)
        return 1;
      int i = ((Comparable<A>) a).compareTo(p.a);
      if (i != 0)
        return i;
      return ((Comparable<B>) b).compareTo(p.b);
    }
  }

  public static Method findMethod(Object o, String method, Object... args) {
    try {
      if (o == null)
        return null;
      if (o instanceof Class) {
        Method m = findMethod_static((Class) o, method, args, false);
        if (m == null)
          return null;
        m.setAccessible(true);
        return m;
      } else {
        Method m = findMethod_instance(o, method, args, false);
        if (m == null)
          return null;
        m.setAccessible(true);
        return m;
      }
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  public static Method findMethod_static(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() & Modifier.STATIC) == 0 || !findMethod_checkArgs(m, args, debug))
          continue;
        return m;
      }
      c = c.getSuperclass();
    }
    return null;
  }

  public static Method findMethod_instance(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) && findMethod_checkArgs(m, args, debug))
          return m;
      }
      c = c.getSuperclass();
    }
    return null;
  }

  public static boolean findMethod_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;
  }

  public static boolean nempty(Collection c) {
    return !empty(c);
  }

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

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

  public static boolean nempty(byte[] o) {
    return !empty(o);
  }

  public static boolean nempty(int[] o) {
    return !empty(o);
  }

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

  public static boolean nempty(Iterator i) {
    return i != null && i.hasNext();
  }

  public static boolean nempty(Object o) {
    return !empty(o);
  }

  public static int hashCodeFor(Object a) {
    return a == null ? 0 : a.hashCode();
  }

  public static boolean empty(Collection c) {
    return c == null || c.isEmpty();
  }

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

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

  public static boolean empty(Object[] o) {
    return o == null || o.length == 0;
  }

  public 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 instanceof byte[])
      return empty((byte[]) o);
    if (o == null)
      return true;
    throw fail("unknown type for 'empty': " + getType(o));
  }

  public static boolean empty(float[] a) {
    return a == null || a.length == 0;
  }

  public static boolean empty(int[] a) {
    return a == null || a.length == 0;
  }

  public static boolean empty(long[] a) {
    return a == null || a.length == 0;
  }

  public static boolean empty(byte[] a) {
    return a == null || a.length == 0;
  }

  public static boolean empty(File f) {
    return getFileSize(f) == 0;
  }

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

  public static long getFileSize(String path) {
    return path == null ? 0 : new File(path).length();
  }

  public static long getFileSize(File f) {
    return f == null ? 0 : f.length();
  }
}