
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int k = scanner.nextInt();
        String s = scanner.next();

        if(s.length() <= k) {
            System.out.println(s);
        }else {
            System.out.println(s.substring(0,k) + "...");
        }
    }

}