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 Set<String> joinCISets(Collection<String>... l) {
  Set<String> set = ciSet();
  for (Collection<String> o : l)
    if (o != null)
      set.addAll(o);
  return set;
}

static Set<String> joinCISets(Iterable<? extends Collection<String>> l) {
  Set<String> set = ciSet();
  if (l != null) for (Collection<String> o : l)
    if (o != null)
      set.addAll(o);
  return set;
}
static TreeSet<String> ciSet() {
  return caseInsensitiveSet();
}


static TreeSet<String> caseInsensitiveSet() {
  return caseInsensitiveSet_treeSet();
}

static TreeSet<String> caseInsensitiveSet(Collection<String> c) {
  return caseInsensitiveSet_treeSet(c);
}


static TreeSet<String> caseInsensitiveSet_treeSet() {
  return new TreeSet(caseInsensitiveComparator());
}

static TreeSet<String> caseInsensitiveSet_treeSet(Collection<String> c) {
  return toCaseInsensitiveSet_treeSet(c);
}


static Comparator<String> caseInsensitiveComparator() {
  
  
  return betterCIComparator();
  
}
static TreeSet<String> toCaseInsensitiveSet_treeSet(Iterable<String> c) {
  if (isCISet(c)) return (TreeSet) c;
  TreeSet<String> set = caseInsensitiveSet_treeSet();
  addAll(set, c);
  return set;
}

static TreeSet<String> toCaseInsensitiveSet_treeSet(String... x) {
  TreeSet<String> set = caseInsensitiveSet_treeSet();
  addAll(set, x);
  return set;
}


static betterCIComparator_C betterCIComparator_instance;

static betterCIComparator_C betterCIComparator() {
  if (betterCIComparator_instance == null)
    betterCIComparator_instance = new betterCIComparator_C();
  return betterCIComparator_instance;
}

static class betterCIComparator_C implements Comparator<String> {
  public int compare(String s1, String s2) {
    if (s1 == null) return s2 == null ? 0 : -1;
    if (s2 == null) return 1;
  
    int n1 = s1.length();
    int n2 = s2.length();
    int min = Math.min(n1, n2);
    for (int i = 0; i < min; i++) {
        char c1 = s1.charAt(i);
        char c2 = s2.charAt(i);
        if (c1 != c2) {
            c1 = Character.toUpperCase(c1);
            c2 = Character.toUpperCase(c2);
            if (c1 != c2) {
                c1 = Character.toLowerCase(c1);
                c2 = Character.toLowerCase(c2);
                if (c1 != c2) {
                    // No overflow because of numeric promotion
                    return c1 - c2;
                }
            }
        }
    }
    return n1 - n2;
  }
}
static boolean isCISet(Iterable<String> l) {
  return l instanceof TreeSet && ((TreeSet) l).comparator() == caseInsensitiveComparator();
}
static <A, B extends A> void addAll(Collection<A> c, Iterable<B> b) {
  if (c != null && b != null) for (A a : b) c.add(a);
}

static <A, B extends A> boolean addAll(Collection<A> c, Collection<B> b) {
  return c != null && b != null && c.addAll(b);
}

static <A, B extends A> boolean addAll(Collection<A> c, B... b) {
  return c != null && c.addAll(Arrays.asList(b));
}



static <A, B> Map<A, B> addAll(Map<A, B> a, Map<? extends A,? extends B> b) {
  if (a != null) a.putAll(b);
  return a;
}

}