class Shape:
       def area(self):
           pass

   class Rectangle(Shape):
   init__init__(self, width, height):
           self.width = width
           self.height = height

       def area(self):
           return self.width * self.height

   class Circle(Shape):
   init__init__(self, radius):
           self.radius = radius
def area(self):
           import math
           return math.pi * self.radius ** 2

   rect = Rectangle(4, 5)
   circ = Circle(3)
   print(rect.area())  # خروجی: 20
   print(circ.area())  # خروجی: 28.274333882308138

   class Employee:
       def init(self, name, salary):
           self.name = name
           self.salary = salary

   class Manager(Employee):
       def give_raise(self, amount):
           self.salary += amount
           print(f"{self.name} has been given a raise. New salary: {self.salary}")

   manager = Manager("Ali", 5000)
   manager.give_raise(1000)  # خروجی: Ali has been given a raise. New salary: 6000