import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String s1 = scan.next();
		String s2 = scan.next();
		scan.close();
		String []str1 = s1.split("[.]");
		String []str2 = s2.split("[.]");

		for(int i = 0; i < str1.length; i++) {
			int k1 = Integer.parseInt(str1[i]);
			int k2 = Integer.parseInt(str2[i]);
			if(k1 > k2) {
				System.out.println("YES");
				System.exit(0);
			}else if(k1 < k2){
				System.out.println("NO");
				System.exit(0);
			}
		}
		System.out.println("YES");
	}
}