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