import java.util.*;
class Main
{
  public static void main(String args[])
  {
    int K;
    Scanner in=new Scanner(System.in);
    K=in.nextInt();
    String S=in.next();
    int l=S.length();
    if(l<=K)
      System.out.println(S);
    else
    {
      String p=S.substring(0,K);
      p=p+"...";
      System.out.println(p);
    }
  }
        
}
/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