#pragma GCC optimize(1)
#pragma GCC optimize(2)
#pragma GCC optimize(3,"Ofast","inline")
#include<bits/stdc++.h>
using namespace std;
void tree(string a,string b){
	if(a.size()<=0)
		return ;
	char c=b[b.size()-1];
	cout<<c;
	tree(a.substr(0,a.find(c)),b.substr(0,a.find(c)));
	tree(a.substr(a.find(c)+1),b.substr(a.find(c),a.size()-a.find(c)-1));
	return ;
} 
int main(){
    string a,b;
    cin>>a>>b;
    tree(a,b);
    return 0;
}