#include<fstream>  
#include<cstring>  
using namespace std;  
ifstream cin("nlr.in");  
ofstream cout("nlr.out");  
string s1,s2;  
int pre(string a,string b)  
{  
	int p=a.find(b[b.length()-1]);  
	cout<<a[p];  
	if(p>0)pre(a.substr(0,p),b.substr(0,p));  
	if(p<a.length()-1)pre(a.substr(p+1,a.length()-p-1),b.substr(p,b.length()-p-1));  
	return 0;  
}  
int main()  
{  
	cin>>s1;  
	cin>>s2;  
	pre(s1,s2);  
	cin.close();  
	cout.close();  
	return 0;  
}