def different_of_cubes(a, b):
    """
    definition: func(a, b) {...}
    objective : gives you the result of the formula different of cubes
                (a-b)^3 = (a-b)(a^2 + ab + b^2)
    """
    result = (a - b) * (a * a + a * b + b * b)
    return result
