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<iostream>

#include <vector>
#include <list>
#include<stack>
#include<queue>
#include<array>

#include <set>
#include<map>

#include<string>
#include<stdlib.h>

#include<algorithm>
#include <functional>
#include<math.h>

#include<fstream>
#include<iomanip>

using namespace std;
using ll = long long;
using ld = long double;
using pii = pair<int,int>;

#define FOR(k,m,n) for(ll (k)=(m);(k)<(n);(k)++)
#define REP(i,n) FOR((i),0,(n))
#define WAITING(str) int str;std::cin>>str;
#define DEBUGING(str) cout<<str<<endl

constexpr int INF = (1 << 30);
constexpr ll INFL = (1ll << 60);
constexpr ll MOD = 1000000007;// 10^9+7


//�ϐ�
ld A, B;






//�T�u�֐�
//����
void input()
{
	cin >> A >> B;
}


//�v�Z
void calc()
{
	constexpr ld pi= 3.141592653589793;
	cout << fixed;
	cout << setprecision(8) << (ld)4 * pi*B*B*B / 3 << endl;
}


//�o��
void output()
{

}


//�f�o�b�O
void debug()
{
	int N;
	cin>>N;
}


//���C���֐�
int main()
{
	input();
	calc();
	output();
	debug();
	
	return 0;
}