q.abs = q.abs.setWord(v1)
	r.neg = even
	q.neg = !even

	r.Mul(A, r)
	q.Mul(B, q)

	A.Add(t, s)
	B.Add(r, q)
}

// euclidUpdate performs a single step of the Euclidean GCD algorithm
// if extended is true, it also updates the cosequence Ua, Ub.
func euclidUpdate(A, B, Ua, Ub, q, r, s, t *Int, extended bool) {
	q, r = q.QuoRem(A, B, r)

	*A, *B, *r = *B, *r, *A

	if extended {