import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n=scan.nextInt();
		String s=scan.next();
		//System.out.println(s.length());
		if(s.length()<=n) System.out.println(s);
		else {
			System.out.println(s.substring(0,n)+""+"...");
			}
	}

} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n=scan.nextInt();
		String s=scan.next();
		//System.out.println(s.length());
		if(s.length()<=n) System.out.println(s);
		else {
			System.out.println(s.substring(0,n)+""+"...");
			}
	}

} Main public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n=scan.nextInt();
		String s=scan.next();
		//System.out.println(s.length());
		if(s.length()<=n) System.out.println(s);
		else {
			System.out.println(s.substring(0,n)+""+"...");
			}
	} main {
		Scanner scan = new Scanner(System.in);
		int n=scan.nextInt();
		String s=scan.next();
		//System.out.println(s.length());
		if(s.length()<=n) System.out.println(s);
		else {
			System.out.println(s.substring(0,n)+""+"...");
			}
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int n=scan.nextInt(); n scan.nextInt() scan.nextInt scan String s=scan.next(); s scan.next() scan.next scan if(s.length()<=n) System.out.println(s);
		else {
			System.out.println(s.substring(0,n)+""+"...");
			} s.length()<=n s.length() s.length s n System.out.println(s) System.out.println System.out System System.out s {
			System.out.println(s.substring(0,n)+""+"...");
			} System.out.println(s.substring(0,n)+""+"...") System.out.println System.out System System.out s.substring(0,n)+""+"..." s.substring(0,n)+""+"..." s.substring(0,n) s.substring s 0 n "" "..." String[] args args public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n=scan.nextInt();
		String s=scan.next();
		//System.out.println(s.length());
		if(s.length()<=n) System.out.println(s);
		else {
			System.out.println(s.substring(0,n)+""+"...");
			}
	}

} public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n=scan.nextInt();
		String s=scan.next();
		//System.out.println(s.length());
		if(s.length()<=n) System.out.println(s);
		else {
			System.out.println(s.substring(0,n)+""+"...");
			}
	}

} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n=scan.nextInt();
		String s=scan.next();
		//System.out.println(s.length());
		if(s.length()<=n) System.out.println(s);
		else {
			System.out.println(s.substring(0,n)+""+"...");
			}
	}

}
