#include <bits/stdc++.h>

using namespace std;

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

int n, S, a[(1 << 12) + 1];
unordered_map<int, int>mp;
long long answer = 0;

int main(){
   ios_base::sync_with_stdio(false);

   fin >> n >> S;
   for (int i = 1; i <= n; i++){
      fin >> a[i];
   }
   for (int i = 1; i <= n; i++){
      for (int j = i + 1; j <= n; j++){
         answer += mp[S - a[i] - a[j]];
      }
      for (int j = 1; j < i; j++){
         ++mp[a[i] + a[j]];
      }
   }
   fout << answer;
}