#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  string s;
  cin >> n;
  cin >> s;
  if (n >= s.length()) {
    cout << s << endl;
  } else {
    for (int i = n; i < n + 3 && i < s.length(); i++) {
      s[i] = '.';
    }
    for (int i = 0; i < n + 3 && i < s.length(); i++) {
      cout << s[i];
    }
    cout << endl;
  }
}
