#include <bits/stdc++.h>
using namespace std;

int main()
{
	int64_t n, x;
	cin >> n >> x;
	vector<int64_t> as(n);
	for (auto &a : as)
	{
		cin >> a;
	}
	sort(as.begin(), as.end());
	int64_t ans = 0;
	for (auto &a : as)
	{
		int64_t b = x - a;
		ans += distance(lower_bound(as.begin(), as.end(), b), upper_bound(as.begin(), as.end(), b));
	}
	cout << ans << endl;
	return 0;
}