C :

#include<stdio.h>
#define PI 3.14159
int main(void){
	double R;
	while(scanf("%lf",&R)!=EOF){
		printf("%.3f\n",R*R*R*PI*(4.0/3.0));
	}
	return 0;
}

C++ :

#include<iostream>
#include<iomanip>
#define PI 3.14159
using namespace std;
int main()
{
	double r;
	while(cin>>r)
	{
		cout<<fixed<<setprecision(3)<<4.0/3*PI*r*r*r<<endl;
	}
	return 0;
}