#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
#include <map>

using namespace std;

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

const int NMAX = 1024 + 1;

int n, lana;
int oaie[NMAX];
map <int, int> sol;

void citeste() {
    f >> n >> lana;
    for (int i = 1; i <= n; i++) f >> oaie[i];
}

void rezolva() {
    long long s, rez = 0;
    for (int i = 1; i < n; i++) {
        for (int j = i + 1; j <= n; j++) {
            s = 1LL * oaie[i] + 1LL * oaie[j];
            if (s > lana) continue;
            rez = rez + sol[lana - s];
        }

        for (int j = 1; j < i; j++) {
            s = 1LL * oaie[i] + 1LL * oaie[j];
            if (s > lana) continue;
            sol[s]++;
        }
    }

    g << rez;
}

int main() {
    citeste();
    rezolva();
    return 0;
}