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)