#include <bits/stdc++.h>
using namespace std;
int main() {
  int k;
  string s;
  cin >> k >> s;
  int n = s.size();
  if (s.size() <= k) {
    cout << s << endl;
    return 0;
  }
  s = s.substr(0, k);
  s += "...";
  cout << s << endl;
}
