217. Two Cylinders
time limit per test: 0.5 sec.
memory limit per test: 65536 KB
input: standard
output: standard



In this problem your task is very simple.

Consider two infinite cylinders in three-dimensional space, of radii R1 and R2 respectively, located in such a way that their axes intersect and are perpendicular.

Your task is to find the volume of their intersection.

Input

Input file contains two real numbers R1 and R2 (1 ≤ R1, R2 ≤ 100);

Output

Output the volume of the intersection of the cylinders. Your answer must be accurate up to 10-4.

Sample test(s)

Input
1 1

Output
5.3333

