#include <iostream>
#include <algorithm>
#include <iterator>
#include <set>
#include <vector>
#include <cmath>
#include <string>

using namespace std;

int main() {
    string s, t;
    cin>>s;
    cin>>t;
    vector <char> v(s.begin(), s.end());
    set <char> st(t.begin(), t.end());
    auto ans = remove_if (v.begin(), v.end(), [st](char &el){
        return st.count(el) == 1;
     });
    copy(v.begin (), ans, ostream_iterator <char> (cout, ""));

    return 0;
}