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 int charArrayIndexOf(char[] a, char [] b, int i) {
  if (a == null) return -1;
  int n = a.length-b.length;
  for (; i < n; i++)
    if (charArrayRegionMatches(a, i, b, 0, b.length))
      return i;
  return -1;
}
static boolean charArrayRegionMatches(char[] a, int aFrom, char[] b, int bFrom, int n) {
  for (int i = 0; i < n; i++)
    if (a[aFrom+i] != b[bFrom+i])
      return false;
  return true;
}

}