import java.util.Scanner;
 
public class Main {
 
	public static void main(String[] args) {

		Scanner in = new Scanner(System.in);
		int k = in.nextInt();
		String s = in.next();
 
		if(s.length() <= k) {
			System.out.println(s);
		}else {
			System.out.println(s.substring(0,k) + "...");
		}
	}
 
}