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 {
public static void main(final String[] args) throws Exception {
assertEqualsVerbose(lithashset('A', 'b', 'k'), charactersAppearingExactlyOnceInEachString(ll("bggkA")));
assertEqualsVerbose(lithashset('A'), charactersAppearingExactlyOnceInEachString(ll("bggkA", "Abbl")));
assertEqualsVerbose(lithashset('A', 'B'), charactersAppearingExactlyOnceInEachString(ll("bggkAB", "BAbbl")));
}
static List ll(A... a) {
ArrayList l = new ArrayList(a.length);
for (A x : a) l.add(x);
return l;
}
static Set charactersAppearingExactlyOnceInEachString(List l) {
Set set = null;
for (String s : l) {
Set newSet = asHashSet(keysWithValue(1, multiSetAsMap(asMultiSet(charsAsList(s)))));
if (set != null) newSet = intersectSets(set, newSet);
set = newSet;
}
return set;
}
static HashSet lithashset(A... items) {
HashSet set = new HashSet();
for (A a : items) set.add(a);
return set;
}
static Map _registerThread_threads = newWeakHashMap();
static Thread _registerThread(Thread t) {
_registerThread_threads.put(t, true);
return t;
}
static void _registerThread() { _registerThread(Thread.currentThread()); }
static void assertEqualsVerbose(Object x, Object y) {
assertEqualsVerbose((String) null, x, y);
}
static void assertEqualsVerbose(String msg, Object x, Object y) {
if (!eq(x, y))
throw fail((msg != null ? msg + ": " : "") + sfu(y) + " != " + sfu(x));
else
print("OK: " + sfu(x));
}
static Map multiSetAsMap(MultiSet ms) {
return multiSetToMap(ms);
}
static HashSet asHashSet(Collection c) {
synchronized(collectionMutex(c)) {
return new HashSet(c);
}
}
static HashSet asHashSet(A[] a) {
return a == null ? null : new HashSet(Arrays.asList(a));
}
static String sfu(Object o) { return structureForUser(o); }
static List charsAsList(final String s) {
return stringAsCharacterList(s);
}
static Map newWeakHashMap() {
return _registerWeakMap(synchroMap(new WeakHashMap()));
}
static boolean eq(Object a, Object b) {
return a == null ? b == null : a == b || a.equals(b);
}
// a little kludge for stuff like eq(symbol, "$X")
static Set intersectSets(Set a, Collection b) {
return setIntersection(a, b);
}
static RuntimeException fail() { throw new RuntimeException("fail"); }
static RuntimeException fail(Throwable e) { throw asRuntimeException(e); }
static RuntimeException fail(Object msg) { throw new RuntimeException(String.valueOf(msg)); }
static RuntimeException fail(String msg) { throw new RuntimeException(msg == null ? "" : msg); }
static RuntimeException fail(String msg, Throwable innerException) { throw new RuntimeException(msg, innerException); }
static volatile StringBuffer local_log = new StringBuffer(); // not redirected
static volatile StringBuffer print_log = local_log; // might be redirected, e.g. to main bot
// in bytes - will cut to half that
static volatile int print_log_max = 1024*1024;
static volatile int local_log_max = 100*1024;
//static int print_maxLineLength = 0; // 0 = unset
static boolean print_silent; // total mute if set
static Object print_byThread_lock = new Object();
static volatile ThreadLocal