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