/*------------------------------------------------------------------------------
 * problem008.cc: common permutations
**----------------------------------------------------------------------------*/

/* Copyright (c) 2009 Peter Bui. All Rights Reserved.
 *
 * Peter Bui <pbui@cse.nd.edu>
 *
**------------------------------------------------------------------------------
 * Includes
**----------------------------------------------------------------------------*/

#include <cstdlib>
#include <algorithm>
#include <iostream>
#include <string>

using namespace std;

/*------------------------------------------------------------------------------
 * Functions
**----------------------------------------------------------------------------*/

string
find_common_permutation(string &s1, string &s2)
{
    string sc = string(s1.size() < s2.size() ? s1.size() : s2.size(), ' ');
    string::iterator it;
	
    sort(s1.begin(), s1.end());
    sort(s2.begin(), s2.end());

    it = set_intersection(s1.begin(), s1.end(), s2.begin(), s2.end(), sc.begin());

    sc.erase(it, sc.end());
    return (sc);
}

/*------------------------------------------------------------------------------
 * Main Execution
**----------------------------------------------------------------------------*/

int
main(int argc, char *argv[]) 
{
    string s1, s2;

    while (true) {
	cin >> s1 >> s2;
	if (cin.eof()) break;

	cout << find_common_permutation(s1, s2) << endl;
    }

    return (EXIT_SUCCESS);
}

/*------------------------------------------------------------------------------
 * vim: sts=4 sw=4 ts=8 ft=cpp
**----------------------------------------------------------------------------*/