import java.util.Scanner;

public class Main{
	public static void main(String args[]){
		Scanner sc=new Scanner(System.in);
		while(sc.hasNext()){
			String[] s1=(sc.next()).split(".");
			String[] s2=(sc.next()).split(".");
			int n=Integer.parseInt(s1[0]+s1[1]+s1[2]);
			int o=Integer.parseInt(s2[0]+s2[1]+s2[2]);
			if(n>o) System.out.println("YES");
			else System.out.println("NO");
		}
	}
}