#include <bits/stdc++.h>
using namespace std;
//前中序建树
string s = "";
void buildPost(string pre ,string in) {
    if (pre == "")
        return;
    char c = pre[0];
    int pos = in.find(c);
    string new_inleft = in.substr(0,pos);
    string new_inright = in.substr(pos+1);

    string new_preleft = pre.substr(1,new_inleft.length());
    string new_preright = pre.substr(1+new_inleft.length());

    buildPost(new_preleft,new_inleft);
    buildPost(new_preright,new_inright);
    s.push_back(c);

}

int main () {
    string pre = "";
    string in = "";
    while (cin >> pre>>in) {
        s="";
        buildPost(pre,in);
        cout<<s<<endl;
    }
}