#include <bits/stdc++.h>
using namespace std;
void solve() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  if (s.size() <= n)
    cout << s;
  else {
    string s1;
    for (int i = 0; i < n; i++) {
      s1 += s[i];
    }
    s1 = s1 + "...";
    cout << s1;
  }
}
int main() {
  solve();
  return 0;
}
