#include <bits/stdc++.h>
using namespace std;
signed main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  int k;
  string s;
  cin >> k >> s;
  if (s.size() > k) {
    cout << s.substr(0, k);
    cout << "...";
    cout << endl;
  } else
    cout << s << endl;
  return 0;
}
