define fast_gcd(a, b) {

	if (a == b) return a;
	if (a > b) return fast_gcd(a - b, b)

	return fast_gcd(a, b - a);
}

define void r_reduce(*r[]) {

	auto g,s;

	if (length(r[]) != 2) sqrt(-1);
	if (scale(r[0])) 2^r[0];
	if (scale(r[1])) 2^r[1];

	if (r[0] >= 0 && r[1] >= 0) g = fast_gcd(r[0], r[1]);
	else g = gcd(r[0], r[1]);

	s = scale;
	scale = 0;

	r[0] /= g;
	r[1] /= g;

	scale = s;
}

define void r_init(*r[], a, b) {
	r[0] = a;
	r[1] = b;
	r_reduce(r[]);
}

define void r_initi(*r[], i, a, b) {

	length(r[]);

	r[0] = i * b + a;
	r[1] = b;

	length(r[]);

	r_reduce(r[]);
}

length(a[])
r_initi(a[], 5, 63, 94);