#include <bits/stdc++.h>

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

map <int,int> H;
int N,A[2000],S,rs;
int main()
{
    fin >>N>>S;
    for (int i=0;i<N;i++) fin >>A[i];
    sort(A,A+N);
    for (int i=0;i<N-1;i++){
        for (int j=i+1;j<N;j++){
            map <int,int>::iterator it=H.find(S-A[i]-A[j]);
            if (it!=H.end()) rs+=it->second;
        }
        for (int j=0;j<i-1;j++){
            H[A[i]+A[j]]++;

        }


    }
    fout<<rs;
    return 0;
}