problem

Given the lengths of $ 2 $ sides that are not the hypotenuse of a right triangle, $ A $ and $ B $. The side of length $ A $ overlaps the $ x $ axis, and the side of length $ B $ overlaps the $ y $ axis.

Do the following:

1. Rotate the triangle around the $ x $ axis.
2. Rotate the shape created by performing the operation $ 1 $ around the $ y $ axis.



Perform the operation $ 2 $ to find the volume of the created figure.



output

Output the volume of the figure. Also, output a line break at the end. Absolute or relative errors less than $ 0.000001 $ are allowed.

Example

Input

1 2


Output

33.510322

Source: aizu | Difficulty: UNKNOWN_DIFFICULTY


Solutions:
import math
(a, b) = map(int, input().split())
print(b ** 3 * math.pi * (4 / 3))


import math
(a, b) = map(int, input().split())
if a > b:
	print(2 / 3 * math.pi * a ** 2 * b)
else:
	print(4 / 3 * math.pi * b ** 3)


from math import pi
(A, B) = map(float, input().split())
print('{:.10f}'.format(4 / 3 * pi * B ** 3))


import math
(a, b) = map(int, input().split())
print(math.pi * float(b) ** 3 * float(4 / 3))


import math
(a, b) = map(int, input().split())
print(4 / 3 * b ** 3 * math.pi)


import math
(a, b) = map(int, input().split())
print(b ** 3 * math.pi * 4 / 3)