Problem: 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

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define REPF(i, a, n) for (int i = (a); i < (int)(n); i++)
#define REP(i, n) REPF(i, 0, n)
#define ALL(x) begin(x),end(x)
#define SZ(x) (int)(x.size())

signed main() {
    cout << setprecision(15) << fixed;
    const double PI = acos(-1);

    int A, B;
    cin >> A >> B;

    if (A < B) {
        cout << 4.0 * PI * B * B * B / 3.0 << endl;
        return 0;
    }
    return 0;
}