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 pad(Object s, int l) {
return pad(s, l, ' ');
}
static String pad(Object s, int l, char c) {
String _s = str(s);
if (lengthOfString(_s) >= l) return _s;
return rep(c, l-lengthOfString(_s)) + _s;
}
static String str(Object o) {
return o == null ? "null" : o.toString();
}
static String str(char[] c) {
return new String(c);
}
static int lengthOfString(String s) {
return s == null ? 0 : s.length();
}
static String rep(int n, char c) {
return repeat(c, n);
}
static String rep(char c, int n) {
return repeat(c, n);
}
static List rep(A a, int n) {
return repeat(a, n);
}
static List rep(int n, A a) {
return repeat(n, a);
}
static String repeat(char c, int n) {
n = Math.max(n, 0);
char[] chars = new char[n];
for (int i = 0; i < n; i++)
chars[i] = c;
return new String(chars);
}
static List repeat(A a, int n) {
n = Math.max(n, 0);
List l = new ArrayList(n);
for (int i = 0; i < n; i++)
l.add(a);
return l;
}
static List repeat(int n, A a) {
return repeat(a, n);
}
}