Michael recently wrote a small piece of code that generates n random numbers. But he found out that the random number generator has a major bug. He observed that in any series ,numbers with a difference of k are often repeated. So he decided to find out that in a series of random numbers how many pairs have a difference of k.

Input

1st line consists of an integer T -no. of test cases

For each test case,

1st line contains -> n & k(n<=25000,1<=k<=n)

2nd line -> array of random numbers (all elements will fit into int)

Output

An integer containing the required answer.

Example

Input:
1
5 3
1 4 2 3 5

 Output:
2

Explanation : 1 and 4, 2 and 5 are the only pairs with their difference as 3.