Cylinder

With a sheet of paper and a pair of scissors, you can cut out two faces and assemble a cylinder as follows:

1. Cut the paper crosswise (parallel to its shorter side) into two rectangular pieces.
2. From the first piece, cut out a circle of the largest possible radius. This circle becomes the base of the cylinder.
3. Roll the second piece so that its perimeter equals the circumference of the circle, then attach one end of the roll to the circle. The roll may overlap itself in order to reach the required perimeter length.

Given the dimensions of the sheet of paper, compute the largest possible volume of a cylinder that can be built with the procedure above.

The input consists of several test cases. Each test case contains two numbers $w$ and $h$ ($1 \le w \le h \le 100$), the width and the height of the sheet of paper.

The last test case is followed by a line containing two zeros.

For each test case, print a single line with the largest possible volume of the cylinder, rounded to three digits after the decimal point.