#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ul = unsigned long;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	ll n, x;
	cin >> n >> x;

	vector<ll> a(n);
	for (auto&& ia : a)
		cin >> ia;

	sort(a.begin(), a.end());
	ll res{ 0 };
	for (int i = 0; i < n; ++i)
	{
		if (a[i] > x)
			break;
		auto it = equal_range(a.begin(), a.end(), x - a[i]);
		if (it.first != a.end() && *it.first == x - a[i])
			res += (it.first == it.second ? 1 : it.second - it.first);
	}

	cout << res << "\n";

	return 0;
}