#include <bits/stdc++.h>

using namespace std;

ifstream in("oite.in");
ofstream out("oite.out");

map <int, int> mp;

int n, target;

int v[1025];

int main()
{
    in >> n >> target;
    int rasp = 0;
    for(int i = 1; i <= n; i++)
    {
        in >> v[i];
    }
    sort(v + 1, v + n + 1);
    for(int i = 1; i < n; i++)
    {
        for(int j = i + 1; j <= n; j++)
        {
            if(v[i] + v[j] > target)
            {
                break;
            }
            rasp += mp[target - v[i] - v[j]];
        }
        for(int j = 1; j < i; j++)
        {
            mp[v[i] + v[j]]++;
        }
    }
    out << rasp;
    return 0;
}