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

int main(void){
    string s;
    int k;
    cin >> k >> s;
    string  a[k];
    if (s.size()<=k){
        cout << s << endl;
    }else{
        for (int i = 0; i < k; i++){
            a[i] = s[i];
        }
        //a[k+1] = "...";
        for (int i = 0; i < k; i++) cout << a[i];
        cout << "...";        
   }
    cout << endl;

}