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
import sys
def parseIntList(str):
 return [long(x) for x in str.split()]
def printBS(li):
 if len(li) is 0:
  print
 else:
  for i in range(len(li)-1):
   print li[i],
  print li[-1]
cases=input()
for case in range(cases):
 p,s=parseIntList(raw_input())
 t=math.sqrt(p*p-24.0*s)/12.0
 l=p/12.0-t
 b=p/12.0+2*t
 print "%.2f"%(l*l*b)