#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: huxuanchen
	Language: C++
	Result: Accepted
	Time:14 ms
	Memory:2076 kb
****************************************************************/