#include<bits/stdc++.h>
 
using namespace std;
int main()
{int n,c,a[1000],t=0;
cin>>n>>c;
for(int i=0;i<n;i++)
{cin>>a[i];
     
}for(int i=0;i<n;i++)
{
    for(int j=0;j<n;j++)
    {if(a[i]-a[j]==c)t=t+1;
         
    }
}cout<<t;
 
    return 0;
}            
/**************************************************************
	Problem: 1767
	User: wangyiyang
	Language: C++
	Result: Accepted
	Time:5 ms
	Memory:2072 kb
****************************************************************/