#include<iostream>
#include<algorithm>
using namespace std;
const int N = 2e5 + 10;

long long a[N];

int find1(int l, int r,int x)
{
	while (l < r)
	{
		int mid = l + r >> 1;
		if (a[mid] >= x)
			r = mid;
		else
			l = mid + 1;
	}
	if (a[l] == x)
		return l;
	else
		return 0;
}
int find2(int l, int r, int x)
{
	while (l < r)
	{
		int mid = l + r + 1 >> 1;
		if (a[mid] <= x)
			l = mid;
		else
			r = mid - 1;
	}
	if (a[l] == x)
		return l;
	else
		return 0;
}
int main()
{
	int n, c;
	int b;
	int sta, en;
	int sum = 0;
	cin >> n >> c;

	for (int i = 0; i < n; i++)
		cin >> a[i];
	sort(a, a + n);
	/*cout << find1(0, n - 1, 3) << endl;
	cout << find2(0, n - 1, 3) << endl;*/

	for (int i = 0; i < n; i++)
	{
		 b = a[i] + c;
		/* cout << b << endl;*/
		sta= find1(0, n - 1, b);
		en= find2(0, n - 1, b);
		if(en!=0&&sta!=0)
		sum += en - sta + 1;
		/*cout << i << " " << sum << " "<<endl;*/

	}
	cout << sum << " "<<endl;
}