#include <bits/stdc++.h>
using namespace std;
const int nax = 1e6 + 5;
void solve() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  if (s.size() <= n)
    cout << s << '\n';
  else
    cout << s.substr(0, n) + "...\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int tc;
  tc = 1;
  while (tc--) {
    solve();
  }
  return 0;
}
