#include <iostream>
#include <cstdio>
#include <cassert>
#include <cmath>
#include <cstring>
#include <vector>
#include <algorithm>
#include <stack>
using namespace std;

vector <char> p;

bool check1[100005], check2[100005];


int main()
{
   string s1,s2;

   cin >> s1 >> s2;

    long long n = s1.length();

    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            {
                if (s1[i] == s2[j] && check1[i] == false && check2[j] == false)
                {
                    p.push_back(s1[i]);
                    check1[i] = true;
                    check2[j] = true;
                }
            }

    long long maxs,x = 0, l = 0;

    n = p.size();

    while (n - l > 0)
    {
        maxs = 0;
        for (int j = x; j < n; j++)
            {
                if (int(p[j]) > maxs)
                    {
                        maxs = int(p[j]);
                        l = j+1;
                    }
            }
        cout << char(maxs);
        //cout << l;
        x = l;
    }
}