Problem: Johnny needs to make a rectangular box for his physics class project. He has bought P cm of wire and S cm^2 of special paper. He would like to use all the wire (for the 12 edges) and paper (for the 6 sides) to make the box.
What is the largest volume of the box that Johnny can make?

Input
The first line contains t, the number of test cases (about 10). Then t test cases follow.

Each test case contains two integers P and S in a line (1 ≤ P ≤ 40000, 1 ≤ S ≤ 20000). You may assume that there always exists an optimal solution for the given input cases.


Output
For each test case, print a real number that is the largest volume of the box that Johnny can make, rounded to two decimal places.

Example

Input:
2
20 14
20 16

Output:
3.00
4.15

Output details
First case: the dimensions of the largest box may be 3, 1 and 1.
Second case: the dimensions of the largest box may be 7/3, 4/3 and 4/3.

Solution (in PYTHON):

Solution:
t=int(raw_input())
for i in xrange(t):
    w=raw_input().split()
    p=int(w[0])
    s=int(w[1])
    x1=p+(p*p-24*s)**(0.5)
    x2=p-(p*p-24*s)**(0.5)
    x1/=12
    x2/=12
    y1=s*x1/2 + x1**3 - p*(x1**2)/4
    y2=s*x2/2 + x2**3 - p*(x2**2)/4
    print '%.2f'%(max(y1,y2))