HDU2002 计算球体积

#include <iostream>
#include <cstdio>

#define PI 3.1415927

using namespace std;
int main()
{
	double r;
	while(cin >> r)
	{
		double V = 4*PI*r*r*r/3;
		printf("%.3f\n", V);
	}
	return 0;
}