use proconio::{fastout, input, marker::Bytes};

#[fastout]
fn main() {
    input! {
        s: Bytes,
    }

    println!("{}", output(solve(s)));
}

fn solve(s: Vec<u8>) -> bool {
    match s[0] {
        b'4' | b'5' => true,
        _ => false,
    }
}

fn output(ans: bool) -> &'static str {
    match ans {
        true => "Yes",
        false => "No",
    }
}