#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pil = pair<pii, int>;
const int INF = 2e9;
int main() {
  int k;
  string s;
  cin >> k >> s;
  int t = s.size();
  if (k < t)
    cout << s.substr(0, k) << "..." << endl;
  else
    cout << s << endl;
}
