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:
test_case = int(raw_input())
for t in range(test_case):
    p, s = map(float, raw_input().split())
    a1 = (p+ (p**2 - 24*s)**0.5)/12.0
    a2 = (p- (p**2 - 24*s)**0.5)/12.0
    print "%.2f"%round(max( s*a1/2 - p*a1*a1/4 + a1*a1*a1, s*a2/2 - p*a2*a2/4 + a2*a2*a2), 2) ## print fixed digits after decimal