Fancy stuff

#[macro_use] extern crate scan_rules;

fn main() {
    loop {
        let_readln!(let num: i64);
        if num == 0 { break; }

        let_readln!(let c1: i64, let a: i64);
        let_readln!(let c2: i64, let b: i64);

        let (a, b, reverse) = if a < b {(a, b, false)} else {(b, a, true)};
        let ratio_a = a as f64 / c1 as f64;
        let ratio_b = b as f64 / c2 as f64;

        if let Some((x, y, gcd)) = eu(a, b, num) {
            let (a, b, x, y, reverse) = {
                if ratio_a > ratio_b {
                    (a/gcd, b/gcd, x, y, reverse)
                } else {
                    (b/gcd, a/gcd, y, x, !reverse)
                }
            };
            let steps = -y/a + if y < 0 {1} else {0}; // y -> 0
            let (x, y) = (gcd*(x - steps * b), gcd*(y + steps * a));
            let (x, y) = if !reverse {(x, y)} else {(y,x)};

            println!("{} {}", x, y);
        } else {
            println!("failure");
        }
    }
}

fn eu(a: i64, b: i64, c: i64) -> Option<(i64, i64, i64)> {
    if b % a == 0 {
        if c % a == 0 {
            Some(((c % b) / a, c / b, a))
        } else { None }
    } else {
        let (r1, r2, gcd) = eu(b % a, a, c)?;
        Some((r2 - (b / a)*r1, r1, gcd))
    }
}