#include <bits/stdc++.h>
#include <iterator>
using namespace std;
#define rep(i, n) for(int i=0; i<n; i++)
#define debug 1
using ll = long long;
using ld = long double;
const int mod = 998244353;
const double pi = atan2(0, -1);
#include <time.h>
#include <chrono>

int main() {
	string S, T;
	int N;
	cin >> S >> T >> N;
	rep(i, N) {
		S += "_" + T;
	}
	cout << S << endl;
}