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


int main(){
  int k;
  string s;
  cin >> k;
  cin >> s;
  if(s.size()<=k){
    cout << s << endl;
  }else{
    for(int i=0;i<k;++i){
      cout << s[i];
    }
    cout << "...";
    cout << endl;
  }
  return 0;
}
