#include <iostream>
#include <fstream>
#include <unordered_map>

using namespace std;
using ll = long long;
unordered_map<int, int>yumpapi;
int v[1030];
int main()
{
    ifstream cin ("oite.in");
    ofstream cout ("oite.out");
    int koi, blana;
    int sum=0;
    ll answear=0;
    cin>>koi>>blana;
    for (int i=1; i<=koi; i++)
    {
        cin>>v[i];
    }
    for (int i=1; i<=koi; i++)
    {
        for (int j=i+1; j<=koi; j++)
        {
            sum=blana-v[i]-v[j];
            if (yumpapi.find(sum)!=yumpapi.end())
            answear=0LL+answear+yumpapi[sum];
        }
        for (int j=1; j<=i-1; j++)
        {
            yumpapi[v[i]+v[j]]++;
        }
    }
    cout<<answear;
}