#include <fstream>
#include <unordered_map>
using namespace std;
ifstream cin("oite.in");ofstream cout("oite.out");
unordered_map<int,int>frv;int v[1050];
int main()
{
    int n,s,rasp=0,i,j;
    cin>>n>>s;
    for(i=1;i<=n;i++) cin>>v[i];
    for(i=1;i<=n;i++){
        for(j=i+1;j<=n;j++) rasp+=frv[s-(v[i]+v[j])];
        for(j=1;j<i;j++) frv[v[i]+v[j]]++;
    }
    cout<<rasp;
    return 0;
}