def test_euclidean(a, b):
    assert euclidean(0, 0) == 0
    assert euclidean(0, 1) == 1
    assert euclidean(1, 0) == 1
    assert euclidean(1, 1) == 1


def test_gcd(a, b):
    assert gcd(a, b) == expected

def test_gcd(a, b):
    assert gcd(a, b) == expected

def test_gcd(a, b):
    assert gcd(a, b) == expected

