一期作业题7

#include<iostream>
#include<stdlib.h>
#include<iomanip>
using namespace std;
#define PI 3.1415927
int main()
{
	double change(double x);
	double line;
	double area;
	while (cin >> line)
	{
		area = (4.0 / 3.0)*PI * line*line*line;
		cout << fixed << setprecision(3) << area << endl;
	}
	return 0;
}