#include<bits/stdc++.h>
using namespace std;
const int N = 4e6+5;
int a[N];
int main(){
    register int n,m,sum=0;
	scanf("%d%d",&n,&m);
	for (register int i = 1;i <= n;++i)scanf("%d",&a[i]);
	sort(a+1,a+n+1);
	for (register int i = n;i > 1;--i){
		for (register int j = i-1;j >= 1;--j){
		    if (a[i] - a[j] > m)break;
		    if (a[i] - a[j] == m)sum++;
		}
	}
	printf("%d",sum);
	return 0;
}