Problem Description

You are given an integer array A and an integer $B.$

You are required to return the count of pairs having sum equal to $B.$ NOTE: pair $($i$,$j$)$ and $($j$,$i$)$ are same.

Problem Constraints

$1A.$size $()10000$

$1A[i]10000$

$1B10000$

Input Format

First argument is an integer array $A.$

Seond argument is an integer B$.$