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> int indexOf_between(List<A> l, A a, int startIndex, int endIndex) {
  if (l == null) return -1;
  for (int i = startIndex; i < endIndex; i++)
    if (eq(l.get(i), a))
      return i;
  return -1;
}
static boolean eq(Object a, Object b) {
  return a == null ? b == null : a == b || b != null && a.equals(b);
}




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

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

}