#include <bits/stdc++.h>

namespace nono {

struct Init {};

void solve([[maybe_unused]] const Init& init) {
    long long n, m;
    std::cin >> n >> m;
    std::vector<long long> a(n);
    for (int i = 0; i < n; i++) std::cin >> a[i];
    if (m % 2 == 1) {
        std::cout << 0 << std::endl;
        return;
    }
    long long half = m / 2;
    std::set<long long> s(a.begin(), a.end());
    long long ans = 0;
    for (auto v: a) {
        if (s.contains(v + half)) {
            ans += n - 2;
        }
    }
    std::cout << ans << std::endl;
}

}  //  namespace nono

int main() {
    std::cin.tie(0)->sync_with_stdio(0);
    std::cout << std::fixed << std::setprecision(16);

    int t = 1;
    nono::Init init;

    while (t--) nono::solve(init);
}