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.*;
import javax.net.ssl.*;
import java.security.SecureRandom;
import java.security.cert.X509Certificate;
import java.text.SimpleDateFormat;
class main {
public static void main(final String[] args) throws Exception {
Set set = weakHashSet();
//S a = "hello", b = "bello";
JButton a = jbutton("A"), b = jbutton("B");
assertFalse(add(set, a));
assertFalse(add(set, b));
assertTrue(add(set, a));
print("OK");
}
static void add(BitSet bs, int i) {
bs.set(i);
}
static boolean add(Collection c, A a) {
return c != null && c.add(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 Object print_byThread_lock = new Object();
static volatile ThreadLocal