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

unordered_map <int, int> m;
unordered_map <int, int> :: iterator it;
const int NMAX = 1026;
int v[NMAX];
int main()
{
    ifstream cin("oite.in");
    ofstream cout("oite.out");

    int n, s, i, j;
    cin >> n >> s;
    for (i = 1; i <= n; i++)
        cin >> v[i];
    int ans = 0;
    sort(v + 1, v + n + 1);
    for (i = 1; i <= n; i++)
    {
        for (j = i + 1; j <= n; j++)
        {
            int sum = v[i] + v[j];
            if (m.find(s - sum) != m.end())
                ans += m[s - sum];
        }
        for (j = 1; j < i; j++)
            m[v[i] + v[j]]++;
    }
    cout << ans;
}