class Sample:
    def __init__(self, a, b):
        self.a = a
        self.b = b

    def plus(self):
        return self.a + self.b

    def minus(self):
        return self.a - self.b

class AdditionalSample:
    def __init__(self, a):
        self.a = a
        self.c = 2

    def power(self):
        return self.a ** self.c



class ExtendedSample(Sample, AdditionalSample):
    def __init__(self, a, b):
        super().__init__(a, b)
        self.c = 2

    def divide(self):
        return self.a / self.b

    def multiply(self):
        return self.a * self.b


a = ExtendedSample(3, 6)

print(a.power())