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

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

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

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

    int64_t sol = 0;
    unordered_map<int, int> sums(n + 1);

    sums[v[1] + v[2]]++;
    for (int i = 3; i < n; i++) {
        for (int j = i + 1; j <= n; 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;
}