Count Pairs with Sum

You are given an integer array A of size N and an integer k. Your task is to count the number of distinct pairs (i, j) with i < j such that:

$A_i + A_j = k$

For example, consider the array [1, 5, 7, -1] with k = 6. The pairs that satisfy the condition are (1, 5) and (7, -1), so the answer is 2.

When there are duplicate numbers in the array, every distinct occurrence is considered a separate element. For instance, in the array [1, 1, 1, 1, 1] with k = 2 there are 10 valid pairs, since any two of the five 1s can form a valid pair.

Note: The solution should process multiple test cases in one execution.

inputFormat

The first line of input contains a single integer T denoting the number of test cases.

Each test case consists of two lines:
The first line contains two integers N and k, where N is the number of elements of the array and k is the target sum.
The second line contains N space-separated integers representing the array A. If N is 0, the second line will be empty.

outputFormat

For each test case, output a single integer on a new line representing the number of distinct pairs (i, j) (with i < j) from the array such that A_i + A_j = k.

## sample

2
4 6
1 5 7 -1
5 2
1 1 1 1 1

2
10

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