#include <bits/stdc++.h>
using namespace std;
const int INF = 1001001001;
int main() {
  int K;
  cin >> K;
  string N;
  cin >> N;
  if (N.size() <= K) {
    cout << N << endl;
  } else {
    N.erase(K, N.size() - K + 1);
    cout << N << "..." << endl;
  }
}
