#include<bits/stdc++.h>
using namespace std;
long long n, a[200010], c, sum = 0;
int main(){
	cin >> n >> c;
	for (int i = 1;i <= n;i++) cin >> a[i];
	for (int i = 1;i < n;i++) {
		for (int j = i + 1;j <= n;j++) {
			int abcd = a[i] - a[j];
			if (abcd < 0)abcd = 0 - abcd;
			if (abcd == c) {
				sum++;
			}
		}
	}
	cout << sum;
}

2 3 4超时了！！！ 求大佬帮助！！！