#include <bits/stdc++.h>
using namespace std;
const long long int N = 200010;
const long long int MOD = 998244353;
long long int mod(long long int n) { return (n % MOD + MOD) % MOD; }
int main() {
  long long int n;
  cin >> n;
  string s;
  cin >> s;
  if (s.size() <= n)
    cout << s << endl;
  else {
    for (long long int i = 0; i < n; i++) {
      cout << s[i];
    }
    cout << "...";
  }
}
