#include <bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pli pair<ll,int>
#define pil pair<int,ll>
#define fi first
#define se second
#define inf (INT_MAX/2-1)
#define infl (1LL<<60)
#define vi vector<int>
#define vl vector<ll>
#define pb push_back
#define sz(a) (int)(a).size()
#define all(a) begin(a),end(a)
#define y0 y5656
#define y1 y7878
#define aaa system("pause");
#define dbg(x) cerr<<(#x)<<": "<<(x)<<'\n',aaa
#define dbga(x,n) cerr<<(#x)<<"[]: ";for(int _=0;_<n;_++)cerr<<x[_]<<' ';cerr<<'\n',aaa
#define dbgs(x) cerr<<(#x)<<"[stl]: ";for(int _:x)cerr<<_<<' ';cerr<<'\n',aaa
#define dbgp(x) cerr<<(#x)<<": "<<x.fi<<' '<<x.se<<'\n',aaa
#define maxn 1024

using namespace std;

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

map<pii,int> hh;///=icm poti sa scrii suma .fi cu un termen din pereche .se
map<int,int> icm;
int v[maxn+5];

int main () {
  int n, m; fin >> n >> m;
  int i, j, z;
  for (i = 1; i <= n; i++) fin >> v[i];
  for (i = 1; i < n; i++)
    for (j = i+1; j <= n; j++) {
      hh[{v[i]+v[j],i}]++;
      hh[{v[i]+v[j],j}]++;
      icm[v[i]+v[j]]++;
    }
  ll ans = 0;
  for (i = 1; i < n; i++)
    for (j = i+1; j <= n; j++) {
      int sum = m-v[i]-v[j];
      ans += icm[sum] - hh[{sum,i}] - hh[{sum,j}] + (v[i] + v[j] == sum);
    }
  fout << ans/6LL;
  fin.close(); fout.close();
  return 0;
}