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 String toStringWithIdentityHashCode(Object o) {
  return withIdentityHash(o, str(o));
}
static String withIdentityHash(Object o, String s) {
  return o == null ? s : addSuffix(s, "@" + intToHex_flexLength(identityHashCode(o)));
}


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

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




static String addSuffix(String s, String suffix) {
  return s == null || s.endsWith(suffix) ? s : s + suffix;
}


static String intToHex_flexLength(int i) {
  return Integer.toHexString(i);
}


static int identityHashCode(Object o) {
  return System.identityHashCode(o);
}



}