#include <fstream>
#include <unordered_map>

using namespace std;

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

int n, l;

int v[1025];

unordered_map < int, int > M;

int main()
{
    f >> n >> l;

    for (int i = 1; i <= n; i++)
        f >> v[i];

    int ans = 0;

    for (int i = 3; i < n; i++)
    {
        for (int j = 1; j < i - 1; j++)
            M[v[i - 1] + v[j]]++;

        for (int j = i + 1; j <= n; j++)
            if (M.count(l - v[i] - v[j]))
                ans += M[l - v[i] - v[j]];
    }

    g << ans << "\n";

    return 0;
}