import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s1 = sc.next();
    String s2 = sc.next();
    String[] s1d = s1.split(".");
    String[] s2d = s2.split(".");
    String ans = "NO";
    for(int i = 0; i < 3; i++) {
      int a = Integer.parseInt(s1d[i]);
      int b = Integer.parseInt(s2d[i]);
      if(a > b) {
        ans = "YES";
        break;
      }
      if(i == 2) ans = "YES";
    }
    System.out.println(ans);
  }
}