Count Pairs with Given Difference

You are given an array of n integers and an integer k. Your task is to determine the number of pairs of indices (i, j) (with i < j) such that the absolute difference between the corresponding elements is exactly k, i.e. \(|arr[i] - arr[j]| = k\).

Example:

Input:
5 2
1 5 3 4 2
Output:
3

</p>

In the above example, the pairs are (1, 3), (5, 3), and (4, 2) resulting in a total count of 3.

inputFormat

The input is read from standard input (stdin) and consists of two lines:

• The first line contains two integers n and k, where n is the number of elements in the array and k is the target absolute difference.
• The second line contains n integers separated by spaces representing the array elements.

outputFormat

Output to standard output (stdout) a single integer that represents the number of pairs in the array that have an absolute difference equal to k.

## sample

5 2
1 5 3 4 2

3