#include <iostream>
using namespace std;
int n, c, ans;
long long a[200001];

int main() {
	cin >> n >> c;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
		for (int j = 1; j < i; j++) {
			if (a[i] - a[j] == c) {
				ans++;
			}
			if (a[j] - a[i] == c) {
				ans++;
			}
		}
	}
	cout << ans << endl;
	return 0;
}