#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  string S;
  cin >> N >> S;
  int len = S.length();
  if (len > N) {
    string substring = S.substr(0, N);
    cout << substring << "...";
  } else {
    cout << S;
  }
  return 0;
}
