import java.util.*;

class Main{
	public static void main(String[] args){
	  Scanner scn = new Scanner(System.in);
      int k = Integer.parseInt(scn.nextLine());
      String s = scn.nextLine();
      if(s.length() < k+1){
        System.out.println(s);
        return;
      }else{
        String ans = s.substring(0,k) + "...";
        System.out.println(ans);
      }
	}
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz