import java.util.Scanner;

public class yukicoder_138 {
	public static void main(String[] args) {
		Scanner stdIn = new Scanner(System.in);
		
		String a = stdIn.nextLine();
		String b = stdIn.nextLine();

		String[] a_str = a.split("\\.");
		String[] b_str = b.split("\\.");
		
		if (a_str[0].compareTo(b_str[0]) == 1) {
			System.out.println("YES");
		} else if (a_str[0].compareTo(b_str[0]) == 0) {
			if (a_str[1].compareTo(b_str[1]) == 1) {
				System.out.println("YES");
			} else if (a_str[1].compareTo(b_str[1]) == 0) {
				if (a_str[2].compareTo(b_str[2]) == 1) {
					System.out.println("YES");
				} else {
					System.out.println("NO");
				}
			} else {
				System.out.println("NO");
			}
		} else {
			System.out.println("NO");
		}
	}
}