use std::io;

fn main() {
    let stdin = io::stdin();
    let mut buf = String::new();

    stdin
        .read_line(&mut buf)
        .unwrap();

    let ab: Vec<u32> = buf.split_whitespace().map(|n| n.parse().unwrap()).collect();

    buf = String::new();

    stdin
        .read_line(&mut buf)
        .unwrap();

    let splited: Vec<&str> = buf.split("-").collect();

    println!("{}", if splited.len() == 2 { "Yes" } else { "No"} );
}