Harvey Specter has agreed to take Mike Ross to a meeting filled with brilliant scientists at NSA Headquarters. But, as always, it's not going to be easy for Mike. He has to solve a puzzle given by Harvey.

Harvey gives two numbers N and K and defines a set A.

A = { x : x is a natural number ≤ N }
(i.e), A = {1,2,3,4,5,6,...., N}

Mike has to find the total number of pairs of elements A[i] and A[j] belonging to the given set, such that, i < j and their sum is divisible by K

Input Format
An integer T followed by T lines, each containing a pair of space separated integers N and K.

Output Format
T integers on separate lines. Each integer denotes the answer corresponding to that test case.

Constraints
1<=T<=100
K<=N<=10⁹
1<=K<=10000

Sample Input

2
10 4
7 3

Sample Output

10
7

Explanation

For the 1^st test case, there are 10 pairs whose sum is divisible by 4.
(1,3), (1,7), (2,6), (2,10), (3,5), (3,9), (4,8), (5,7), (6,10) and (7,9)

For the 2^nd test case, there are 7 pairs whose sum is divisible by 3.
(1,2), (1,5), (2,4), (2,7), (3,6), (4,5) and (5,7)