#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {

    int k; cin >> k;
    string s; cin >> s;
    string ans;
    if (s.size() <= k) ans = s;
    else {
        ans = s.substr(0, k);
        ans += "...";
    }
    cout << ans << endl;
    return 0;
}
//abc168

#include <bits/stdc++.h>
#include <string>
using namespace std;

int main() {
  int k;
  string s;
  cin >> k >> s;

  if(s.size() <= k){
    cout << s;
  }else{
    cout << s.substr(0,k) << "..." << endl;
  }

}
