#include<bits/stdc++.h>
using namespace std;
long long a[100000000], c, ans, n;
int main() {
	cin >> n >> c;
	for (long long i = 1; i <= n; i++) {
		cin >> a[i];
		for (long long j = 1; j <= i; j++) {
			if(a[i]!=a[j]&&abs(a[i]-a[j])==c){
				ans++;
			}
		}
	}
	cout<<ans;
	return 0;
}

本蒟蒻只会暴力导致TLE