You are given with an array of integers and an integer K. You have to find and print the count of all such pairs which have difference K.

Note: Take absolute difference between the elements of the array.

Input Format:

The first line of input contains an integer, that denotes the value of the size of the array. Let us denote it with the symbol n.
The following line contains n space separated integers, that denote the value of the elements of the array.
The following line contains an integer, that denotes the value of K.

Output format :

The first and only line of output contains count of all such pairs which have an absolute difference of K. 

Constraints :

0 <= n <= 10^4
Time Limit: 1 sec