**Problem**
When chomping a tree the beaver cuts a very specific shape out of the tree
trunk. What is left in the tree trunk looks like two frustums of a cone joined
by a cylinder with the diameter the same as its height. A very curious beaver
tries not to demolish a tree but rather sort out what should be the diameter of
the cylinder joining the frustums such that he chomped out certain amount of
wood. You are to help him to do the calculations.

We will consider an idealized beaver chomping an idealized tree. Let us assume
that the tree trunk is a cylinder of diameter **D** and that the beaver
chomps on a segment of the trunk also of height **D**. What should be the
diameter **d** of the inner cylinder such that the beaver chmped out **V**
cubic units of wood?

Input contains multiple cases each presented on a separate line. Each line
contains two integer numbers **D** and **V** separated by whitespace. **D**
is the linear units and **V** is in cubic units. **V** will not exceed the
maximum volume of wood that the beaver can chomp. A line with **D**=0 and **V**=0
follows the last case.

For each case, one line of output should be produced containing one number
rounded to three fractional digits giving the value of **d** measured in
linear units.

### Sample input

10 250
20 2500
25 7000
50 50000
0 0

### Output for sample input

8.054
14.775
13.115
30.901