use std::io;

fn main() {
    let mut str = String::new();
    io::stdin().read_line(&mut str).ok().expect("piyo");
    let v : Vec<u64> = str.split_whitespace().map(|x|x.parse().ok().expect("foo")).collect();
    str = String::new();
    io::stdin().read_line(&mut str).ok().expect("piyo");
    let w = str.split_whitespace().map(|x| x.parse::<u64>().ok().expect("bar")).fold(0, |a, b| a + b);
    if v[0] * v[1] == w {
        println!("YES");
    } else {
        println!("NO");
    }
}