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> A navigableSet_find(NavigableSet<A> set, A a) {
  if (set == null || a == null) return null;
  A b = set.floor(a);
  return b != null && sortedSet_compare(set, a, b) == 0 ? b : null;
}
static <A> int sortedSet_compare(SortedSet<A> set, A a, A b) {
  return compareWithComparator(set.comparator(), a, b);
}


static <A> int compareWithComparator(Comparator<A> comparator, A a, A b) {
  return comparator == null ? cmp(a, b) : comparator.compare(a, b);
}


static int cmp(Number a, Number b) {
  return a == null ? b == null ? 0 : -1 : cmp(a.doubleValue(), b.doubleValue());
}

static int cmp(double a, double b) {
  return a < b ? -1 : a == b ? 0 : 1;
}

static int cmp(Object a, Object b) {
  if (a == null) return b == null ? 0 : -1;
  if (b == null) return 1;
  return ((Comparable) a).compareTo(b);
}

}