#include<bits/stdc++.h>

using namespace std;

#define rep(i, l, n) for(int i = int(l); i < int(n); i++)
#define ll long long
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

template<class T> bool chmin(T &a, T b) {if(a > b) {a = b; return true;} return false;}
template<class T> bool chmax(T &a, T b) {if(a < b) {a = b; return true;} return false;}
template<class T> using spq = priority_queue<T, vector<T>, greater<T>>;

// bool -> Yes/No
string answer(bool b) {return b ? "Yes" : "No";}

void fix(int k) {cout << fixed << setprecision(k);}

const int inf = 2e9;
const long long INF = 2e18;
const long double eps = 1e-12;
const long double pi = acos(-1);
int dx[] = {0, -1, 0, 1, -1, -1, 1, 1}, dy[] = {1, 0, -1, 0, 1, -1, -1, 1};

void main_program() {
    int n; cin >> n;
    long a[n];
    rep(i, 0, n) cin >> a[i];
    multiset<long> s;
    rep(i, 0, n) s.insert(a[i]);
    long ans = INF;
    long type[] = {INF, -INF};
    rep(i, 0, n) {
        s.erase(s.find(a[i]));
        if(a[i] >= 0) chmin(ans, (*prev(s.end())) * a[i]), chmin(type[0], a[i]);
        else chmin(ans, (*s.begin()) * a[i]), chmax(type[1], a[i]);
        s.insert(a[i]);
    }
    if(type[0] != INF && type[1] != -INF) {
        chmin(ans, type[0] * type[1]);
    }
    cout << ans << "\n";
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T = 1;
    cin >> T;
    while(T--) {
        main_program();
    }
}