#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  string s;
  cin >> s;
  if (s.length() > N) {
    for (int i = 0; i < N; i++) {
      cout << s[i];
    }
    cout << "...";
  } else {
    cout << s;
  }
  return 0;
}
