from abc import ABC, abstractmethod


class Shape(ABC):
# Shape is an abstract base class

    @abstractmethod
    def area(self):
        pass


class Circle(Shape):
# Circle is a class that inherits from the abstract Shape class

    def __init__(self, radius):
    	self.radius = radius
	
    def area(self):
   	# As a child of an Abstract class, this child class MUST define
    #	it's own implementation of this abstractmethod
    	return 3.14 * self.radius ** 2


class Square(Shape):
# Square is a class that inherits from the abstract Shape class

    def __init__(self, side):
    	self.side = side

    def area(self):
    # As a child of an Abstract class, this child class MUST define
    #	it's own implementation of this abstractmethod
    	return self.side ** 2