def areMultiples(x: int, y: int) -> bool:
    """Return True if x and y are multiples of each other, False otherwise."""
    if x == 0 or y == 0:
        return True
    return (not y % x) or (not x % y)


print("Testing areMultiples()...", end="")
assert areMultiples(2, 4) == True  # 4 is a multiple of 2
assert areMultiples(400, 200) == True  # 400 is a multiple of 200
assert areMultiples(0, 100) == True  # 0 is a multiple of 100
assert areMultiples(123, 0) == True  # 0 is a multiple of 123
assert areMultiples(888, 888) == True  # 888 is a multiple of itself
assert areMultiples(-50, 100) == True  # 100 is a multiple of -50
assert areMultiples(50, -100) == True  # -100 is a multiple of 50
assert areMultiples(-50, -100) == True  # -100 is a multiple of -50
assert areMultiples(400, 250) == False
assert areMultiples(3, 100) == False
assert areMultiples(-3, 100) == False
print("Passed!")