#include <bits/stdc++.h>

using namespace std;

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

using ll = long long;

const int MOD = 666013;

struct Hash {
  vector<vector<pair<int, int>>> h;
  void add(int x) {
    int xh = (ll)37 * x % MOD;
    bool added = false;
    for (auto &val : h[xh])
      if (val.first == x) {
        val.second++;
        added = true;
        break;
      }
     if (!added)
      h[xh].emplace_back(x, 1);
  }
  int count(int x) {
    int xh = (ll)37 * x % MOD;
    int ans = 0;
    for (auto val : h[xh])
      if (val.first == x)
        return val.second;
    return 0;
  }
  Hash() : h(MOD, vector<pair<int, int>>{}) {}
};

int main() {
  ios_base::sync_with_stdio(false);
  in.tie(NULL);
  out.tie(NULL);
  int n, l; in >> n >> l;
  vector<int> a(n);
  for (int &x : a)
    in >> x;
  sort(a.begin(), a.end());
  Hash H;
  ll ans = (ll)0;
  for (int i = 0; i < n - 1; i++) {
    for (int j = i + 1; j < n; j++)
      if (l - a[i] - a[j] < 0)
        break;
      else {
        int x = l - a[i] - a[j];
        ans += H.count(x);
      }
    for (int j = 0; j < i; j++)
      H.add(a[i] + a[j]);
  }
  out << ans << "\n";
  return 0;
}