fn main() {
    let stdin = std::io::read_to_string(std::io::stdin()).unwrap();
    let mut stdin = stdin.lines();

    let s: String = stdin.next().unwrap().parse().unwrap();

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

fn solve(s: String) -> bool {
    s.bytes().enumerate().all(|(i, s)| match i & 1 {
        0 => (s as char).is_ascii_lowercase(),
        1 => s == b' ',
        _ => unreachable!(),
    })
}

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