fn remaining(total: u32, done: u32) -> u32 { total.saturating_sub(done) }
fn main() {
    assert_eq!(remaining(4,1),3);
    assert_eq!(remaining(4,4),0);
    assert_eq!(remaining(4,5),0);
    assert_eq!(remaining(0,0),0);
    println!("Pumasa");
}