import math 


class Shape:
    def area(self):
        return 0.0

    def perimeter(self):
        return 0.0


class Circle(Shape):
    def __init__(self, radius):
        self.radius = radius

    def area(self):
        return math.pi * self.radius**2

    def perimeter(self):
        return 2 * math.pi * self.radius


class Rectangle(Shape):
    def __init__(self, length, width):
        self.length = length
        self.width = width

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

    def perimeter(self):
        return 2 * (self.length + self.width)


# Main part of the script
if __name__ == "__main__":

    circle_instance = Circle(5.0)
    print("Circle - Area:", circle_instance.area())
    print("Circle - Perimeter:", circle_instance.perimeter())

    print()

    rectangle_instance = Rectangle(4.0, 6.0)
    print("Rectangle - Area:", rectangle_instance.area())
    print("Rectangle - Perimeter:", rectangle_instance.perimeter())