use std::io::Read;

fn solve(s: &str) {
    let not_ushitap: bool = s.chars().enumerate()
        .any(|(i, c)| !(i % 2 == 0 && c.is_alphabetic()) && !(i % 2 == 1 && c.is_ascii_whitespace()));
    if not_ushitap {
        println!("{}", "No");
    } else {
        println!("{}", "Yes");
    }
}

fn main() {
    let mut s = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let s = s.trim().split('\n').next().unwrap().trim();
    solve(s);
}