#include <math.h>
#include <iomanip>
//#include <cstdio>
//#include <cmath>



using namespace std;

int main() {
     double r,p;
    cout << "Hello, World!" << endl;
    cout <<"podaj promien kuli"<<endl;
    cin >>r;

    p = (4/3)*pow(r,3)*M_PI;
    //cout<<setprecision(2)<<p<<endl;
    printf ("%.2f",p);

    return 0;
}