from abc import ABC, abstractmethod

class A(ABC):
    def __init__(self):
        pass

    def method(self):
        print("1")

    @abstractmethod
    def x(self):
        pass

class B(A):
    def __init__(self):
        pass

    def method2(self):
        print("2")

class C(B):
    def __init__(self):
        pass

    def method(self):
        print("X")

    def method2(self):
        print("Y")

    def x(self):
        pass

c = C()
c.method()
c.method2()