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

string getS(string a1,string a2){
    if(a1.size()==0||a2.size()==0)return "";
    int i = a2.find(a1[0]);
    return getS(a1.substr(1,i),a2.substr(0,i))+getS(a1.substr(i+1),a2.substr(i+1))+a1[0];
}

int main()
{
    string a1,a2;
    cin>>a1>>a2;
    cout<<getS(a1,a2)<<endl;
    return 0;
}