#include <fstream>
#include <unordered_map>

using namespace std;

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

int c, l, a[1024], nr;
unordered_map <int, int> mp;

int main(){

        in >> c >> l;
        for(int i = 1; i <= c; i++)
                in >> a[i];

        for(int i = 2; i <= c; i++) {
                for(int j = i + 1; j <= c; j++)
                        if(mp.find(l - a[i] - a[j]) != mp.end())
                                nr += mp[l - a[i] - a[j]];
                for(int j = 1; j < i; j++) {
                        mp[a[i] + a[j]]++;
                }
        }

        out << nr;

        return 0;
}