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 A vStackComputeWithPrintStruct(VStack.Computable computation) {
if (computation == null) return null;
VStack stack = new VStack(computation);
stepAllWithPrintStruct(stack);
return (A) stack.result();
}
static void stepAllWithPrintStruct(Steppable s) {
if (s == null) return;
do {
printStruct(s);
} while (s.step());
printStruct(s);
}
static A printStruct(String prefix, A a) {
printStructure(prefix, a);
return a;
}
static A printStruct(A a) {
printStructure(a);
return a;
}
static A printStructure(String prefix, A o) {
if (endsWithLetter(prefix)) prefix += ": ";
print(prefix + structureForUser(o));
return o;
}
static A printStructure(A o) {
print(structureForUser(o));
return o;
}
static boolean endsWithLetter(String s) {
return nempty(s) && isLetter(last(s));
}
static volatile StringBuffer local_log = new StringBuffer(); // not redirected
static volatile Appendable 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 boolean print_silent = false; // total mute if set
static Object print_byThread_lock = new Object();
static volatile ThreadLocal