using System;

public class Program {
	public static void Main(string[] args) {
		string[] a = Console.ReadLine().Split('.');
		string[] b = Console.ReadLine().Split('.');
		
		for (int i = 0; i < a.Length; i++) {
			if (int.Parse(b[i]) < int.Parse(a[i])) {
				Console.WriteLine("YES");
				return;
			} else if (int.Parse(b[i]) > int.Parse(a[i])) {
				Console.WriteLine("NO");
				return;
			}
		}
		Console.WriteLine("YES");
	}
}