use std::io;
use std::str::FromStr;

fn main() {
    let stdin = io::stdin();
    let mut buf = String::new();
    stdin.read_line(&mut buf).ok();

    let mut it = buf.split_whitespace().map(|n| String::from_str(n).unwrap());
    let a = it.next().unwrap();

    let mut buf = String::new();
    stdin.read_line(&mut buf).ok();

    let mut it = buf.split_whitespace().map(|n| String::from_str(n).unwrap());
    let b = it.next().unwrap();

    let mut veca = Vec::new();
    let mut vecb = Vec::new();
    let split_a = a.split(".");
    let split_b = b.split(".");



    for aa in split_a {
        veca.push(aa);
    }
    for bb in split_b {
        vecb.push(bb);
    }


    for i in 0..3 {
        if veca[i] == vecb[i] {
            continue;
        }
        if veca[i] > vecb[i] {
            println!("YES");
            return;
        } else {
            println!("NO");
            return;
        }
    }
    println!("NO");
}