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

using ll = long long;

int main(void) {
	int N, X;
	cin >> N >> X;
	vector<int> a(N);
	for(int i = 0; i < N; ++i) cin >> a[i];
	
	sort(a.begin(), a.end());
	ll ans = 0;
	for(auto x : a) ans += (upper_bound(a.begin(), a.end(), X - x) - lower_bound(a.begin(), a.end(), X - x));
	cout << ans << endl;
	return 0;
}