import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String a0 = sc.next();
		String a1 = sc.next();
		String[] s1 = a0.split("\\.");
		String[] s2 = a1.split("\\.");
		String ans = "";
		for(int i = 0 ; i < s1.length ; i++) {
			if(s1[i].compareTo(s2[i]) > 0) {
				ans = "YES";
				break;
			} else if(s1[i].compareTo(s2[i]) < 0){
				ans = "NO";
				break;
			} else if(s1[i].compareTo(s2[i]) == 0 && i == 2) {
				ans = "YES";
			}
		}
		System.out.println(ans);
 	}
}