fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    let s = s.trim();
    println!("{}",
        if s.contains('x') {
            (1usize << 32) - s[1..].parse::<usize>().unwrap()
        } else {
            s.parse().unwrap()
        }
    );
}