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 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.*;
public class main {


public static void main(String[] args) throws Exception {
  String[] a = retypeArray(new Object[] {"a", "b"}, String.class);
  printStructure(a);
  print(a.getClass());
}

static <A> A[] retypeArray(Object[] array, Class<A> c) {
  A[] a = makeArray(c, l(array));
  System.arraycopy(array, 0, a, 0, l(array));
  return a;
}
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 void print() {
  print("");
}

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

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 void printStructure(String prefix, Object o) {
  print(prefix + structure(o));
}

static void printStructure(Object o) {
  print(structure(o));
}



static <A> A[] makeArray(Class<A> type, int n) {
  return (A[]) Array.newInstance(type, n);
}
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 int l(Object o) {
  return l((List) o); // incomplete
}

static String structure(Object o) {
  HashSet refd = new HashSet();
  return structure_2(structure_1(o, new structure_Data(refd)), refd);
}

// leave to false, unless unstructure() breaks
static boolean structure_allowShortening = false;

static int structure_shareStringsLongerThan = 20;

static class structure_Data {
  int stringSizeLimit;
  IdentityHashMap<Object, Integer> seen = new IdentityHashMap<Object, Integer>();
  HashSet<Integer> refd;
  HashMap<String, Integer> strings = new HashMap<String, Integer>();
  HashSet<String> concepts = new HashSet<String>();
  Class conceptClass = findClass("Concept");
  
  structure_Data(HashSet<Integer> refd) {
  this.refd = refd;}
}

static String structure_1(Object o, structure_Data d) {
  if (o == null) return "null";
  
  // these are never back-referenced (for readability)
  
  if (o instanceof BigInteger)
    return "bigint(" + o + ")";
  
  if (o instanceof Double)
    return "d(" + quote(str(o)) + ")";
    
  if (o instanceof Float)
    return "fl " + quote(str(o));
    
  if (o instanceof Long)
    return o + "L";
  
  if (o instanceof Integer)
    return str(o);
    
  if (o instanceof Boolean)
    return ((Boolean) o).booleanValue() ? "t" : "f";
    
  if (o instanceof Character)
    return quoteCharacter((Character) o);
    
  if (o instanceof File)
    return "File " + quote(((File) o).getPath());
    
  // referencable objects follow
  
  Integer ref = d.seen.get(o);
  if (ref != null) {
    d.refd.add(ref);
    return "r" + ref;
  }
      
  if (o instanceof String && (ref = d.strings.get((String) o)) != null) {
    d.refd.add(ref);
    return "r" + ref;
  }
  
  ref = d.seen.size()+1;
  d.seen.put(o, ref);
  String r = "m" + ref + " "; // marker

  if (o instanceof String) {
    String s = d.stringSizeLimit != 0 ? shorten((String) o, d.stringSizeLimit) : (String) o;
    if (l(s) >= structure_shareStringsLongerThan)
      d.strings.put(s, ref);
    return r + quote(s);
  }
    
  String name = o.getClass().getName();

  StringBuilder buf = new StringBuilder();
  
  if (o instanceof HashSet)
    return r + "hashset " + structure_1(new ArrayList((Set) o), d);

  if (o instanceof TreeSet)
    return r + "treeset " + structure_1(new ArrayList((Set) o), d);
  
  if (o instanceof Collection) {
    for (Object x : (Collection) o) {
      if (buf.length() != 0) buf.append(", ");
      buf.append(structure_1(x, d));
    }
    return r + "[" + buf + "]";
  }
  
  if (o instanceof Map) {
    for (Object e : ((Map) o).entrySet()) {
      if (buf.length() != 0) buf.append(", ");
      buf.append(structure_1(((Map.Entry) e).getKey(), d));
      buf.append("=");
      buf.append(structure_1(((Map.Entry) e).getValue(), d));
    }
    return r + (o instanceof HashMap ? "hm" : "") + "{" + buf + "}";
  }
  
  if (o.getClass().isArray()) {
    if (o instanceof byte[])
      return "ba " + quote(bytesToHex((byte[]) o));

    int n = Array.getLength(o);

    if (o instanceof boolean[]) {
      String hex = boolArrayToHex((boolean[]) o);
      int i = l(hex);
      while (i > 0 && hex.charAt(i-1) == '0' && hex.charAt(i-2) == '0') i -= 2;
      return "boolarray " + n + " " + quote(substring(hex, 0, i));
    }

    for (int i = 0; i < n; i++) {
      if (buf.length() != 0) buf.append(", ");
      buf.append(structure_1(Array.get(o, i), d));
    }
    return r + "array{" + buf + "}";
  }

  if (o instanceof Class)
    return r + "class(" + quote(((Class) o).getName()) + ")";
    
  if (o instanceof Throwable)
    return r + "exception(" + quote(((Throwable) o).getMessage()) + ")";
    
  if (o instanceof BitSet) {
    BitSet bs = (BitSet) o;
    for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) {
      if (buf.length() != 0) buf.append(", ");
       buf.append(i);
    }
    return "bitset{" + buf + "}";
  }
    
  // Need more cases? This should cover all library classes...
  if (name.startsWith("java.") || name.startsWith("javax."))
    return r + String.valueOf(o);
    
  String shortName = o.getClass().getName().replaceAll("^main\\$", "");
  
  if (shortName.equals("Lisp")) {
    buf.append("l(" + structure_1(getOpt(o, "head"), d));
    List args = (List) ( getOpt(o, "args"));
    if (nempty(args))
      for (int i = 0; i < l(args); i++) {
        buf.append(", ");
        Object arg = args.get(i);
        
        // sweet shortening
        if (arg != null && eq(arg.getClass().getName(), "main$Lisp") && isTrue(call(arg, "isEmpty")))
          arg = get(arg, "head");
          
        buf.append(structure_1(arg, d));
      }
    buf.append(")");
    return r + str(buf);
  }
    
  int numFields = 0;
  String fieldName = "";
  if (shortName.equals("DynamicObject")) {
    shortName = (String) get_raw(o, "className");
    Map<String, Object> fieldValues = (Map) get_raw(o, "fieldValues");
    
    for (String _fieldName : fieldValues.keySet()) {
      fieldName = _fieldName;
      Object value = fieldValues.get(fieldName);
      if (value != null) {
        if (buf.length() != 0) buf.append(", ");
        buf.append(fieldName + "=" + structure_1(value, d));
      }
      ++numFields;
   }
  } else {
    // regular class
    
    Class c = o.getClass();
    
    if (d.conceptClass != null && d.conceptClass.isInstance(o) && !d.concepts.contains(c.getName())) {
      d.concepts.add(c.getName());
      r += "c ";
    }
    
    while (c != Object.class) {
      List<Field> fields = asList(c.getDeclaredFields());
      for (int i = 1; i < l(fields); i++)
        if (eq(fields.get(i).getName(), "this$1")) {
          swapElements(fields, 0, i);
          break;
        }
      for (Field field : fields) {
        if ((field.getModifiers() & (Modifier.STATIC | Modifier.TRANSIENT)) != 0)
          continue;
        fieldName = field.getName();
        
        // skip outer object reference
        //if (fieldName.indexOf("$") >= 0) continue;
  
        Object value;
        try {
          field.setAccessible(true);
          value = field.get(o);
        } catch (Exception e) {
          value = "?";
        }
        
        // put special cases here...
    
        if (value != null) {
          if (buf.length() != 0) buf.append(", ");
          buf.append(fieldName + "=" + structure_1(value, d));
        }
        ++numFields;
      }
      c = c.getSuperclass();
    }
  }
  
  String b = buf.toString();
  
  if (numFields == 1 && structure_allowShortening)
    b = b.replaceAll("^" + fieldName + "=", ""); // drop field name if only one
  String s = shortName;
  if (buf.length() != 0)
    s += "(" + b + ")";
  return r + s;
}

// drop unused markers
static String structure_2(String s, HashSet<Integer> refd) {
  List<String> tok = javaTok(s);
  StringBuilder out = new StringBuilder();
  for (int i = 1; i < l(tok); i += 2) {
    String t = tok.get(i);
    if (t.startsWith("m") && isInteger(t.substring(1))
      && !refd.contains(parseInt(t.substring(1))))
      continue;
    out.append(t).append(tok.get(i+1));
  }
  return str(out);
}



// replacement for class JavaTok
// maybe incomplete, might want to add floating point numbers
// todo also: extended multi-line strings

static int javaTok_n, javaTok_elements;
static boolean javaTok_opt;

static List<String> javaTok(String s) {
  return javaTok(s, null);
}

static List<String> javaTok(String s, List<String> existing) {
  ++javaTok_n;
  int nExisting = javaTok_opt && existing != null ? existing.size() : 0;
  List<String> tok = existing != null ? new ArrayList(nExisting) : new ArrayList();
  int l = s.length();
  
  int i = 0, n = 0;
  while (i < l) {
    int j = i;
    char c; String cc;
    
    // scan for whitespace
    while (j < l) {
      c = s.charAt(j);
      cc = s.substring(j, Math.min(j+2, l));
      if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
        ++j;
      else if (cc.equals("/*")) {
        do ++j; while (j < l && !s.substring(j, Math.min(j+2, l)).equals("*/"));
        j = Math.min(j+2, l);
      } else if (cc.equals("//")) {
        do ++j; while (j < l && "\r\n".indexOf(s.charAt(j)) < 0);
      } else
        break;
    }
    
    if (n < nExisting && javaTok_isCopyable(existing.get(n), s, i, j))
      tok.add(existing.get(n));
    else
      tok.add(quickSubstring(s, i, j));
    ++n;
    i = j;
    if (i >= l) break;
    c = s.charAt(i); // cc is not needed in rest of loop body
    cc = s.substring(i, Math.min(i+2, l));

    // scan for non-whitespace
    if (c == '\'' || c == '"') {
      char opener = c;
      ++j;
      while (j < l) {
        if (s.charAt(j) == opener || s.charAt(j) == '\n') { // end at \n to not propagate unclosed string literal errors
          ++j;
          break;
        } else if (s.charAt(j) == '\\' && j+1 < l)
          j += 2;
        else
          ++j;
      }
    } else if (Character.isJavaIdentifierStart(c))
      do ++j; while (j < l && (Character.isJavaIdentifierPart(s.charAt(j)) || "'".indexOf(s.charAt(j)) >= 0)); // for stuff like "don't"
    else if (Character.isDigit(c)) {
      do ++j; while (j < l && Character.isDigit(s.charAt(j)));
      if (j < l && s.charAt(j) == 'L') ++j; // Long constants like 1L
    } else if (cc.equals("[[")) {
      do ++j; while (j+1 < l && !s.substring(j, j+2).equals("]]"));
      j = Math.min(j+2, l);
    } else if (cc.equals("[=") && i+2 < l && s.charAt(i+2) == '[') {
      do ++j; while (j+2 < l && !s.substring(j, j+3).equals("]=]"));
      j = Math.min(j+3, l);
    } else
      ++j;

    if (n < nExisting && javaTok_isCopyable(existing.get(n), s, i, j))
      tok.add(existing.get(n));
    else
      tok.add(quickSubstring(s, i, j));
    ++n;
    i = j;
  }
  
  if ((tok.size() % 2) == 0) tok.add("");
  javaTok_elements += tok.size();
  return tok;
}

static List<String> javaTok(List<String> tok) {
  return javaTok(join(tok), tok);
}

static boolean javaTok_isCopyable(String t, String s, int i, int j) {
  return t.length() == j-i
    && s.regionMatches(i, t, 0, j-i); // << could be left out, but that's brave
}
static String substring(String s, int x) {
  return safeSubstring(s, x);
}

static String substring(String s, int x, int y) {
  return safeSubstring(s, x, y);
}
static <A> ArrayList<A> asList(A[] a) {
  return new ArrayList<A>(Arrays.asList(a));
}

static ArrayList<Integer> asList(int[] a) {
  ArrayList<Integer> l = new ArrayList();
  for (int i : a) l.add(i);
  return l;
}

static <A> ArrayList<A> asList(Iterable<A> s) {
  if (s instanceof ArrayList) return (ArrayList) s;
  ArrayList l = new ArrayList();
  if (s != null)
    for (A a : s)
      l.add(a);
  return l;
}
  public static String bytesToHex(byte[] bytes) {
    return bytesToHex(bytes, 0, bytes.length);
  }

  public static String bytesToHex(byte[] bytes, int ofs, int len) {
    StringBuilder stringBuilder = new StringBuilder(len*2);
    for (int i = 0; i < len; i++) {
      String s = "0" + Integer.toHexString(bytes[ofs+i]);
      stringBuilder.append(s.substring(s.length()-2, s.length()));
    }
    return stringBuilder.toString();
  }

static void swapElements(List l, int i, int j) {
  if (i == j) return;
  Object o = l.get(i);
  l.set(i, l.get(j));
  l.set(j, o);
}
static boolean isInteger(String s) {
  return s != null && Pattern.matches("\\-?\\d+", s);
}
  static String quote(String s) {
    if (s == null) return "null";
    return "\"" + s.replace("\\", "\\\\").replace("\"", "\\\"").replace("\r", "\\r").replace("\n", "\\n") + "\"";
  }
  
  static String quote(long l) {
    return quote("" + l);
  }
  
  static String quote(char c) {
    return quote("" + c);
  }

static String shorten(String s, int max) {
  if (s == null) return "";
  return s.length() <= max ? s : s.substring(0, Math.min(s.length(), max)) + "...";
}
// get purpose 1: access a list/array (safer version of x.get(y))

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

static Class get_dynamicObject = findClass("DynamicObject");

// 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);
    }
      
    if (get_dynamicObject != null && get_dynamicObject.isInstance(o))
      return call(get_raw(o, "fieldValues"), "get", field);
  } 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() & 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 String quoteCharacter(char c) {
  if (c == '\'') return "'\\''";
  if (c == '\\') return "'\\\\'";
  return "'" + c + "'";
}

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();
}
// currently finds only inner classes of class "main"
// returns null on not found
// this is the simple version that is not case-tolerant
static Class findClass(String name) {
  if (!isJavaIdentifier(name)) return null;
  try {
    return Class.forName("main$" + name);
  } catch (ClassNotFoundException e) {
    return null;
  }
}
static boolean eq(Object a, Object b) {
  if (a == null) return b == null;
  if (a.equals(b)) return true;
  if (a instanceof BigInteger) {
    if (b instanceof Integer) return a.equals(BigInteger.valueOf((Integer) b));
    if (b instanceof Long) return a.equals(BigInteger.valueOf((Long) b));
  }
  return false;
}
static String str(Object o) {
  return String.valueOf(o);
}
  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() & 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 int parseInt(String s) {
  return empty(s) ? 0 : Integer.parseInt(s);
}
// hmm, this shouldn't call functions really. That was just
// for coroutines.
static boolean isTrue(Object o) {
  if (o instanceof Boolean)
    return ((Boolean) o).booleanValue();
  if (o == null) return false;
  return ((Boolean) callF(o)).booleanValue();
}

static boolean isTrue(Object pred, Object arg) {
  return booleanValue(callF(pred, arg));
}
static Object getOpt(Object o, String field) {
  if (o instanceof String) o = getBot ((String) o);
  if (o == null) return null;
  if (o instanceof Class) return getOpt((Class) o, field);
  
  if (o.getClass().getName().equals("main$DynamicObject"))
    return ((Map) getOpt_raw(o, "fieldValues")).get(field);
  
  if (o instanceof Map) return ((Map) o).get(field);
  
  return getOpt_raw(o, field);
}

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

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

static Field getOpt_findStaticField(Class<?> c, String field) {
  Class _c = c;
  do {
    for (Field f : _c.getDeclaredFields())
      if (f.getName().equals(field) && (f.getModifiers() & Modifier.STATIC) != 0)
        return f;
    _c = _c.getSuperclass();
  } while (_c != null);
  return null;
}

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 String boolArrayToHex(boolean[] a) {
  return bytesToHex(boolArrayToBytes(a));
}


static Object callF(Object f, Object... args) {
  return callFunction(f, args);
}
static Object callFunction(Object f, Object... args) {
  if (f == null) return null;
  if (f instanceof Runnable) {
    ((Runnable) f).run();
    return null;
  } else if (f instanceof String)
    return call(mc(), (String) f, args);
  else
    return call(f, "get", args);
  //else throw fail("Can't call a " + getClassName(f));
}
static boolean empty(Collection c) {
  return isEmpty(c);
}

static boolean empty(String s) {
  return isEmpty(s);
}

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);
  throw fail("unknown type for 'empty': " + getType(o));
}
// hopefully covers all cases :)
static String safeSubstring(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 String safeSubstring(String s, int x) {
  return safeSubstring(s, x, l(s));
}

static RuntimeException asRuntimeException(Throwable t) {
  return t instanceof RuntimeException ? (RuntimeException) t : new RuntimeException(t);
}
static Object getBot(String botID) {
  return callOpt(getMainBot(), "getBot", botID);
}

  public static String join(String glue, Iterable<String> strings) {
    StringBuilder buf = new StringBuilder();
    Iterator<String> 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 String join(Iterable<String> strings) {
    return join("", strings);
  }
  
  public static String join(String[] strings) {
    return join("", strings);
  }

static byte[] boolArrayToBytes(boolean[] a) {
  byte[] b = new byte[(l(a)+7)/8];
  for (int i = 0; i < l(a); i++)
    if (a[i])
      b[i/8] |= 1 << (i & 7);
  return b;
}
// 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 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 boolean booleanValue(Object o) {
  return eq(true, o);
}
static String quickSubstring(String s, int i, int j) {
  if (i == j) return "";
  return s.substring(i, j);
}
static boolean isJavaIdentifier(String s) {
  if (s.length() == 0 || !Character.isJavaIdentifierStart(s.charAt(0)))
    return false;
  for (int i = 1; i < s.length(); i++)
    if (!Character.isJavaIdentifierPart(s.charAt(i)))
      return false;
  return true;
}


static Object callOpt(Object o) {
  if (o == null) return null;
  return callF(o);
}

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

static Method callOpt_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() & Modifier.STATIC) == 0 || !callOpt_checkArgs(m, args, debug))
        continue;

      return m;
    }
    c = c.getSuperclass();
  }
  return null;
}

static Method callOpt_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) && callOpt_checkArgs(m, args, debug))
        return m;
    }
    c = c.getSuperclass();
  }
  return null;
}

private static boolean callOpt_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 Object mainBot;

static Object getMainBot() {
  return mainBot;
}
static Class mc() {
  return getMainClass();
}
  static RuntimeException fail() {
    throw new RuntimeException("fail");
  }
  
  static RuntimeException fail(Object msg) {
    throw new RuntimeException(String.valueOf(msg));
  }
  
  static RuntimeException fail(String msg) {
    throw new RuntimeException(unnull(msg));
  }
   
  // disabled for now to shorten some programs 
  /*static RuntimeException fail(S msg, O... args) {
    throw new RuntimeException(format(msg, args));
  }*/
static String getType(Object o) {
  return getClassName(o);
}



  static String unnull(String s) {
    return s == null ? "" : s;
  }
  
  static <A> List<A> unnull(List<A> l) {
    return l == null ? emptyList() : l;
  }
  
  static <A> Iterable<A> unnull(Iterable<A> i) {
    return i == null ? emptyList() : i;
  }
  
  static Object[] unnull(Object[] a) {
    return a == null ? new Object[0] : a;
  }
static Class getMainClass() { try {
 
  return Class.forName("main");

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}

static Class getMainClass(Object o) { try {
 
  return (o instanceof Class ? (Class) o : o.getClass()).getClassLoader().loadClass("main");

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
static String getClassName(Object o) {
  return o == null ? "null" : o.getClass().getName();
}


static List emptyList() {
  return new ArrayList();
  //ret Collections.emptyList();
}

}