#include<bits/stdc++.h> using namespace std; string s1,s2; void ask(string s1,string s2){ if(s1.size()>0&&s2.size()>0){ char ch=s1[s1.size()-1]; cout<<ch; int f=s2.find(ch); ask(s1.substr(0,f),s2.substr(0,f)); ask(s1.substr(f,s1.size()-f-1),s2.substr(f+1)); } } int main(){ cin>>s1>>s2; ask(s1,s2); return 0; }