Cylinder

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Chef wants to make a steel container. The container should be of cylindrical form and should have as large volume as possible. He has a rectangular steel sheet of the size W × H for this. His plan is the following:
 At first he cuts the sheet into two rectangular sheets by horizontal or vertical cut.
 Then he takes one of the obtained sheets and cuts out two equal nonoverlapping circles from it. Let the radius of each circle be R.
 Finally he cuts out the rectangular sheet of the size 2πR × A for maximal possible A from the second sheet, with sizes parallel to the sides of the second sheet. He will use it as a lateral surface of the container. Namely, he rolls up the obtained sheet along the side 2πR to obtain the lateral surface of cylinder.
 Thus, Chef obtains the cylindrical container of height A and radius R, having bottom and top made from steel.
Chef is aware of your advanced math abilities and asks you for help to find the optimal container. Output the maximum volume of the container that could be achieved by the above scheme.
Input
The first line of the input contains an integer T denoting the number of test cases. The description of T test cases follows. The only line of each test case contains two spaceseparated integers W and H.
Output
For each test case, output a single line containing the maximum volume of the container. Your answer will be considered as correct if it has a relative error less than 10^{−11}. More formally, if the correct output is A and your output is B, your output will be considered as correct if and only if A − B ≤ 10^{−11} * A.
Constrains
 1 ≤ T ≤ 400000 (4 * 10^{5})
 1 ≤ W ≤ 999999 (10^{6} − 1)
 1 ≤ H ≤ 999999 (10^{6} − 1)
Example
Input: 3 4 4 2 3 1 6 Output: 3.471819240663 0.824190535860 0.785398163397
Explanation
In all examples blue circles are top and bottom of container. Yellow rectangle is used to create lateral surface. Namely, we roll up it along the direction of blue arrow to match green borders.
Example case 1:
R ≅ 0.63662, A ≅ 2.72676.
Example case 2:
R ≅ 0.36218, A = 2.
Example case 3:
R = 0.5, A = 1.
Author:  anton_lunyov 
Tester:  laycurse 
Editorial  http://discuss.codechef.com/problems/CYLINDER 
Tags  anton_lunyov, april13, maths, medium 
Date Added:  11032013 
Time Limit:  1 sec 
Source Limit:  50000 Bytes 
Languages:  C, CPP14, JAVA, PYTH, PYTH 3.5, CS2, PAS fpc, PAS gpc, RUBY, PHP, GO, NODEJS, HASK, SCALA, D, PERL, FORT, WSPC, ADA, CAML, ICK, BF, ASM, CLPS, PRLG, ICON, SCM qobi, PIKE, ST, NICE, LUA, BASH, NEM, LISP sbcl, LISP clisp, SCM guile, JS, ERL, TCL, PERL6, TEXT, CLOJ, FS 
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