uva 10252

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define test int t; cin>>t; for(int cs=1;cs<=t;cs++)
int main()
{
    string a, b;
    while (getline(cin, a), getline(cin, b))
    {
        int aCounts[128], bCounts[128];
        for (int i = 'a'; i <= 'z'; ++i)
            aCounts[i] = bCounts[i] = 0;

        for (int i = 0; i < a.size(); ++i)
            ++aCounts[a[i]];

        for (int i = 0; i < b.size(); ++i)
            ++bCounts[b[i]];

        string longest = "";


        for (int i = 'a'; i <= 'z'; ++i)
            while (aCounts[i] > 0 && bCounts[i] > 0)
            {
                longest += (char) i;
                --aCounts[i];
                --bCounts[i];
            }

        cout << longest << '\n';
    }
}