use std::io::stdin;

fn main() {
    let mut s = String::new();
    stdin().read_line(&mut s).unwrap();

    for (i, c) in s.trim().chars().enumerate() {
        match i % 2 {
            0 if c.is_ascii_lowercase() => {}
            1 if c == ' ' => {}
            _ => return println!("No"),
        }
    }
    println!("Yes");
}