#include <bits/stdc++.h>
using namespace std;
int main() {
  int k;
  cin >> k;
  string str;
  cin >> str;
  int w = str.size();
  if (k > w) {
    cout << str << endl;
  } else {
    str = str.substr(0, k);
    str = str + "...";
    cout << str << endl;
  }
}
