#include <fstream>
#include <algorithm>
#include <unordered_map>
using namespace std;
ifstream cin("oite.in");
ofstream cout("oite.out");
int v[1025],n,sol,sum;
unordered_map<int,int>mp;
int main()
{
    cin>>n>>sum;
    for(int i=1;i<=n;i++)
        cin>>v[i];
    sort(v+1,v+n+1);
    for(int i=1;i<=n;i++){
        for(int j=i+1;j<=n;j++){
            sol+=mp[sum-v[i]-v[j]];
        }
        for(int j=1;j<i;j++)
            mp[v[i]+v[j]]++;
    }
    cout<<sol;
    return 0;
}