#include<fstream>
#include<unordered_map>
#include<algorithm>
using namespace std;

ifstream in("oite.in");
ofstream out("oite.out");

unordered_map<int, int> mp;

int v[1050];

int main()
{
	int N, S;

	in >> N >> S;

	for (int i = 1;i <= N;++i)
		in >> v[i];

	sort(v + 1, v + N + 1);
	int rez = 0;
	for (int i = 1;i <= N;++i)
	{
		for (int j = i+1;j <= N;++j)
		{
			if (S - v[i] - v[j] >= 0)
				rez += mp[S - v[i] - v[j]];
		}
		for (int j = 1;j<i;++j)
			mp[v[i] + v[j]] += 1;
	}
	out << rez;

	return 0;
}