#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
using vi = vector<int>;
using vii = vector<vi>;
int main() {
  int k;
  string s;
  cin >> k >> s;
  int l;
  l = s.size();
  string ans;
  if (k < l) {
    for (int i = 0; i < k; i++) {
      ans += s[i];
    }
    ans += "...";
    cout << ans << endl;
  } else {
    cout << s << endl;
  }
}
