#include <bits/stdc++.h>

void solve() {
  long long ans = 1LL << 60;
  int n;
  std::cin >> n;
  std::vector<int> X, Y;
  for (int i = 0; i < n; i++) {
    int a;
    std::cin >> a;
    if (a > 0) {
      X.push_back(a);
    }
    if (a < 0) {
      Y.push_back(a);
    }
    if (a == 0) {
      ans = 0;
    }
  }
  std::sort(X.begin(), X.end());
  std::sort(Y.begin(), Y.end());
  if ((int)X.size() == 0) {
    std::cout << std::min(ans, 1LL * Y[0] * Y.back()) << '\n';
  } else if ((int)Y.size() == 0) {
    std::cout << std::min(ans, 1LL * X[0] * X.back()) << '\n';
  } else {
    std::cout << std::min(ans, 1LL * X[0] * Y.back()) << '\n';
  }
}

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  int tc;
  std::cin >> tc;
  for (;tc--;) {
    solve();
  }
}