#include<stdio.h>
long long int h[100005], l;
long long int comp_h(long long int a, long long int b)
{
	if (h[a] > h[b])
		return 1;
	else
		return -1;
}
void swap_h(long long int a, long long int b)
{
	long long int f = h[a];
	h[a] = h[b];
	h[b] = f;
	return;
}
void push(long long int ne)
{
	h[l] = ne;
	long long int p = l++;
	for (; p > 0; p = (p - 1) / 2)
		if (comp_h((p - 1) / 2, p) > 0)
			swap_h((p - 1) / 2, p);
	return;
}
long long int pop()
{
	swap_h(0, --l);
	long long int p = 0;
	for (;;)
	{
		if (2 * p + 2 < l)
		{
			if (comp_h(2 * p + 1, 2 * p + 2) > 0)
			{
				if (comp_h(p, 2 * p + 2) > 0)
					swap_h(p, 2 * p + 2);
				p = 2 * p + 2;
			}
			else
			{
				if (comp_h(p, 2 * p + 1) > 0)
					swap_h(p, 2 * p + 1);
				p = 2 * p + 1;
			}
		}
		else if (2 * p + 1 < l)
		{
			if (comp_h(p, 2 * p + 1) > 0)
				swap_h(p, 2 * p + 1);
			p = 2 * p + 1;
		}
		else
			break;
	}
	return h[l];
}
long long int sorted[100005];
long long int n, d;
long long int find(long long int v)
{
	long long int min, mid, max;
	min = -1;
	max = n;
	while (max - min > 1)
	{
		mid = (max + min) / 2;
		if (sorted[mid] < v)
			min = mid;
		else
			max = mid;
	}
	if (sorted[max] != v)
		max = -1;
	return max;
}
long long int a[100005];
long long int cnt[100005], left[100005], right[100005];
int main()
{
	scanf("%d %d", &n, &d);
	long long int i, j;
	for (i = 0; i < n; i++)
		scanf("%lld", &a[i]);
	l = 0;
	for (i = 0; i < n; i++)
		push(a[i]);
	for (i = 0; i < n; i++)
		sorted[i] = pop();
	sorted[n] = -1;
	for (i = 0; i < n; i++)
		cnt[i] = 0;
	for (i = 0; i < n; i++)
	{
		j = find(a[i] - d);
		if (j < 0)
			left[i] = 0;
		else
			left[i] = cnt[j];
		j = find(a[i]);
		cnt[j]++;
	}
	for (i = 0; i < n; i++)
		cnt[i] = 0;
	for (i = n - 1; i >= 0; i--)
	{
		j = find(a[i] + d);
		if (j < 0)
			right[i] = 0;
		else
			right[i] = cnt[j];
		j = find(a[i]);
		cnt[j]++;
	}
	long long int ans = 0;
	for (i = 0; i < n; i++)
		ans += left[i] * right[i];
	printf("%lld\n", ans);
	return 0;
}