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

using namespace std;

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

unordered_map <int, int> Hash;
int n, sum, v[1050], ans;

int main()
{
    fin >> n >> sum;
    for(int i = 1; i <= n; i++)
        fin >> 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] > sum)
                break;
            int rest = sum - v[i] - v[j];
            if(Hash.find(rest) != Hash.end())
                ans += Hash[rest];
        }
        for(int j = 1; j < i; j++)
            Hash[v[i] + v[j]]++;
    }
    fout << ans;
    return 0;
}