class shape:
__x = 0
__y = 0
class Rectangle(shape):
__l = 0
__m = 0
def __init__(self, x, y):
self.__l = x
self.__m = y
print(self.GetArea())
def GetArea(self):
return self.__l*self.__m
class Circle(shape):
__r = 0
def __init__(self, x):
self.__r = x
print('{:g}'.format(self.GetArea()))
def GetArea(self):
return self.__r**2*3.14
class Square(Rectangle):
__a = 0
def __init__(self, x):
self.__a = x
print(self.GetArea())
def GetArea(self):
return self.__a**2
l, m = map(int, input().split())
r = int(input())
a = int(input())
myRect = Rectangle(l, m)
myCirc = Circle(r)
mySqua = Square(a)