import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.Set;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final int n = sc.nextInt();
		
		final String input = sc.next();
		
		if(n >= 4){
			System.out.println("YES");
		}else if(n == 1){
			System.out.println("NO");
		}else{
			final int num = Integer.parseInt(input, 2);
			if(n == 3){
				System.out.println(num == 2 || num == 5 ? "NO" : "YES");
			}else{
				System.out.println(num == 1 || num == 2 ? "NO" : "YES");
			}
		}
		
	}

}