#include <iostream>
#include <cmath>
#include <string>
using namespace std;

bool a1[256],a2[256];

int main() {

    string s1,s2;

    cin>>s1>>s2;

    for (int i = 0; i < s1.size(); i++){
        a1[(int)s1[i]] = true;
    }

    for (int i = 0; i < s2.size();i++){
        a2[(int)s2[i]] = true;
    }

    for (int i = 0; i < 256;i++){
        if (a1[i] && a2[i]){
         cout<< (char)i;
        }
    }

    return 0;

}