import java.util.*;

class Main {
	static Scanner sc = new Scanner(System.in);
	public static void main(String[] args) {
		
		String[] a = sc.next().split("\\.",0);
		String[] b = sc.next().split("\\.",0);
		String ans = "YES";
		
		
		for (int i=0; i<3; i++) {
			int t1 = Integer.parseInt(b[i]);
			int t2 = Integer.parseInt(a[i]);
			
			if (t1 < t2) {
				ans = "YES"; break;
			}
			else if (t1 > t2) {
				ans = "NO"; break;
			}
		}
		System.out.println(ans);
		
	}
}