#include <stdio.h>
#include<string.h>
#include <math.h>
#include<map>
using namespace std;

int main()
{
	map<int, int>hash;
	int n, c, a[200005], ans = 0;
	scanf("%d%d", &n, &c);
	for (int i = 1; i <= n; i++)
	{
		scanf("%d", &a[i]);
		hash[a[i] + c]++;
	}
	for (int i = 1; i <= n; i++)
	{
		if (hash[a[i]] > 0)ans += hash[a[i]];
	}
	printf("%d", ans);
	return 0;
}