fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let a: isize = itr.next().unwrap().parse().unwrap();
    let b: isize = itr.next().unwrap().parse().unwrap();
    let x = std::cmp::min(a, b);
    let y = (a + b) / 4;
    let z = (a + b) / 4 + 1;
    let mut ans = (a + b - 4 * x).abs();
    if y <= x {
        ans = std::cmp::min(ans, (a + b - 4 * y).abs());
    }
    if z <= x {
        ans = std::cmp::min(ans, (a + b - 4 * z).abs());
    }
    println!("{}", ans);
}