---

class Cat:
    name = "Barsik"
    age = 3

    def say_meow(self):
        print("Meow!")


class Calculator:
    def add(self, a, b):
        return a + b

    def sub(self, a, b):
        return a - b

    def mul(self, a, b):
        return a * b

    def div(self, a, b):
        return a / b if b != 0 else "Error"