#include <bits/stdc++.h>

using namespace std;
ifstream in("oite.in");
ofstream out("oite.out");
int c,v[1025],l,k,ans,s;
map<int,int> mp;
int main()
{
   in>>c>>l;
   for(int i=1;i<=c;i++) in>>v[i];
   for(int i=2;i<=c;i++)
   {
       for(int j=i+1;j<=c;j++)
         if(v[i]+v[j]<=l) ans+=mp[l-v[i]-v[j]];
       for(int j=i-1;j>0;j--)
        mp[v[i]+v[j]]++;
   }
   out<<ans;
}