#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: linyuhang
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2076 kb
****************************************************************/