fn run() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    for (i, c) in s.trim().chars().enumerate() {
        match (i % 2 == 0, c.is_ascii_lowercase(), c == ' ') {
            (true, true, false) => (),
            (false, false, true) => (),
            _ => {
                println!("No");
                return;
            },
        }
    }
    println!("Yes");
}

fn main() {
    run();
}