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