#include<bits/stdc++.h>
using namespace std;
int a[1005];
int main(){
	int n,m,sum=0;
	scanf("%d%d",&n,&m);
	for (int i = 1;i <= n;++i){
		scanf("%d",&a[i]);
	}
	sort(a,a+n);
	//for (int i = 1;i <= n;++i)printf("%d",a[i]);
	for (int i = n;i >= 1;--i){
		for (int j = i-1;j >= 1;--j){
			if (a[i] - a[j] == m){
				sum++;
			}
		}
	}
	printf("%d",sum);
	return 0;
}