zoj 1904 Beavergnaw

#include <iostream>#include <iomanip>#include <cmath>using namespace std;int main(void){    const double pi = 3.1415927;    int D,V;    double d;    while(cin>>D>>V && D && V)    {        d = pow((pow(D,3.0)-6*V/pi),1.0/3);        cout<<fixed<<setprecision(3)<<d<<endl;    }return 0;}