import java.io.*;
import java.util.*;

class Main138 {
	
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		System.out.println(br.readLine().compareTo(br.readLine()) < 0 ? "NO" : "YES");
		
	}
}