#include <bits/stdc++.h>

#define endl "\n"
#define x first
#define y second
#define pb(a) push_back(a);
#define mst(a, x) memset(a, x, sizeof a)
#define all(a) a.begin(), a.end()
#define complete_unique(a) a.erase(unique(a.begin(), a.end()), a.end())

using namespace std;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PII;

const int INF = 0x3f3f3f3f, MOD = 1e9 + 7;

void solve() {
  string s, t;
  cin >> s >> t;
  int n;
  cin >> n;
  while (n--) {
    s += "_" + t;
  }
  cout << s << endl;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  // cout.tie(nullptr);
  int T = 1;
  // cin >> T;
  while (T--) solve();

  return 0;
}