#include <bits/stdc++.h>
using namespace std;
 int main(){
	string s1,s2;
	int p;
    cin>>s2>>s1;
    cin>>p;
    cout<<s1.insert(p,s2);;
    return 0;
}
/**************************************************************
	Problem: 2020
	User: xuanhua
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2076 kb
****************************************************************/