import java.util.Scanner;
public class Main {

	public static void main(String[] args) {

		String ans ="";
		Scanner scan_1 = new Scanner(System.in);
		int num  = scan_1.nextInt();
		String str = scan_1.next();


		int nagasa = str.length();

		if(nagasa <= num) {
			ans = str;
		}else {
			ans = str.substring(0, num)+"...";
		}

		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