package hop_qua;
import java.util.Scanner;

public class Hop_Qua {

    public static double Nghiem(double a, double b,double c)
    {
        double x1,x2;
        double dt=b*b-4*a*c;
        if(dt<0) return 0;
        else if(dt==0)
        {
            x1=-b/2/a;
            if(x1<0) return 0;
            else return x1;
        }else
        {
            x1=(-b+Math.sqrt(dt))/2/a;
            x2=(-b-Math.sqrt(dt))/2/a;
            if(x1<0||x2<0) return 0;
            else
            {
                if(x1<x2) return x1;
                else return x2;
            }
        }
    }
    public static void main(String[] args) {
        Scanner Sc=new Scanner(System.in);
        double x,y;
        x=Sc.nextDouble();
        y=Sc.nextDouble();
        double h=Nghiem(12, -4*(x+y), x*y);
        double v=4*h*h*h-2*(x+y)*h*h+x*y*h;
        System.out.println(""+v);
    }

}