#include <vector>
#include <algorithm>

#include <utility>
#include <fstream>

using std::sort;
using std::vector;

using std::pair;
using std::make_pair;

std::ifstream fin("oite.in");
std::ofstream fout("oite.out");

class HashTable {
  private:
    int MOD;
    vector<vector<pair<int, int>>> table;

  public:
    HashTable(int MOD) {
        this->MOD = MOD;
        table.resize(MOD);
    }

    int& operator[](int val) {
        int hash = val % MOD;
        for (auto& it : table[hash])
            if (it.first == val)
                return it.second;

        table[hash].push_back(make_pair(val, 0));
        return table[hash].back().second;
    }
};

int main() {
    int n, s;
    fin >> n >> s;

    vector<int> v(n + 1);
    for (int i = 1; i <= n; i++)
        fin >> v[i];
    sort(v.begin() + 1, v.end());

    int64_t sol = 0;
    HashTable sums(7919);

    sums[v[1] + v[2]]++;
    for (int i = 3; i < n; i++) {
        for (int j = i + 1; j <= n; j++)
            if (s >= v[i] + v[j])
                sol += sums[s - v[i] - v[j]];

        for (int j = i - 1; j >= 1; j--)
            sums[v[i] + v[j]]++;
    }

    fout << sol << '\n';
    fout.close();
    return 0;
}