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:
import math
output = list()
val = raw_input()
t = int(val)
for i in range(t) :
	nums = list()
	string1 = raw_input()
	nums = string1.split()
	a = float(nums[0])
	b = float(nums[1])
	bh = ((a/2.0)-math.sqrt(math.pow((a/2.0),2)-(6*b)))/6.0
	l = (a/4.0)-(2*bh)
	v = (math.pow(bh,2))*l
	output.append(v)
for i in range(t) :
	print("%.2f" %output[i])