#ifdef poe
#define debug(x) cerr<<#x<<": "<<x<<endl
#else
#define debug(x)
#endif
#include<bits/stdc++.h>
using namespace std;
using ll=long long;
using ull=unsigned long long;
using ld=long double;
using pi=pair<int,int>;
using pll=pair<ll,ll>;
using str=string;
template<class T>using vec=vector<T>;
using vi=vec<int>;using vvi=vec<vi>;using vvvi=vec<vvi>;using vvvvi=vec<vvvi>;using vvvvvi=vec<vvvvi>;
using vll=vec<ll>;using vvll=vec<vll>;using vvvll=vec<vvll>;using vvvvll=vec<vvvll>;using vvvvvll=vec<vvvvll>;
using vpi=vec<pi>;using vvpi=vec<vpi>;using vvvpi=vec<vvpi>;using vvvvpi=vec<vvvpi>;using vvvvvpi=vec<vvvvpi>;
using vpll=vec<pll>;using vvpll=vec<vpll>;using vvvpll=vec<vvpll>;using vvvvpll=vec<vvvpll>;using vvvvvpll=vec<vvvvpll>;
template<class T>using pq=priority_queue<T,vector<T>>;
template<class T>using pqg=priority_queue<T,vector<T>,greater<T>>;
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define loop(i, l, r) for (int i=(int)(l); i<(int)(r); i++)
#define per(i,n) for(int i=(int)(n)-1;0<=i;i--)
#define per1(i,n) for(int i=(int)(n);0<i;i--)
#define range(i,x) for(auto&i:x)
#define range2(i,j,x) for(auto&[i,j]:x)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define Sort(x) sort((x).begin(),(x).end())
#define troS(x) sort((x).rbegin(),(x).rend())
#define Reverse(x) reverse((x).begin(),(x).end())
#define uniq(x) sort((x).begin(),(x).end());(x).erase(unique((x).begin(),(x).end()),(x).end())
#define nextp(x) next_permutation((x).begin(),(x).end())
#define nextc(x,k) next_combination((x).begin(),(x).end(),k)
#define bit(x,i) (((x)>>(i))&1)
#define pf push_front
#define pb push_back
#define df pop_front
#define db pop_back
#define fi first
#define se second
#define elif else if
#define Yes cout<<"Yes"<<'\n'
#define No cout<<"No"<<'\n'
#define YN(x) cout<<((x)?"Yes":"No")<<'\n'
#define O(x) cout<<(x)<<'\n'
#define ismid(a,b,c) ((a)<=(b)&&(b)<(c))
template<class S,class T>bool chmin(S&a,T b){if(a>b){a=b;return true;}return false;}
template<class S,class T>bool chmax(S&a,T b){if(a<b){a=b;return true;}return false;}
template<class T>bool next_combination(T l,T r,int k){T m=l+k;if(l==r||l==m||r==m)return false;T t=m;while(l!=t){t--;if(*t<*(r-1)){T d=m;while(*t>=*d)d++;iter_swap(t,d);rotate(t+1,d+1,r);rotate(m,m+(r-d)-1,r);return true;}}rotate(l,m,r);return false;}
template<class T>T Min(T a,T b){return a<b?a:b;}
template<class T,class...Args>T Min(T a,T b,Args...args){return Min(Min(a,b),args...);}
template<class T>T Max(T a,T b){return a>b?a:b;}
template<class T,class...Args>T Max(T a,T b,Args...args){return Max(Max(a,b),args...);}
template<class T>T Sum(T a){return a;}
template<class T,class... Args>T Sum(T a,Args... args){return a+Sum(args...);}
template<class T>T Max(const vector<T>&v){return *max_element(all(v));}
template<class T>T Min(const vector<T>&v){return *min_element(all(v));}
template<class T>T Sum(const vector<T>&v){return accumulate(all(v),T(0));}
template<class S,class T>T Max(const pair<S,T>&p){return max(p.first,p.second);}
template<class S,class T>T Min(const pair<S,T>&p){return min(p.first,p.second);}
template<class S,class T>T Sum(const pair<S,T>&p){return p.first+p.second;}
template<class S,class T>istream&operator>>(istream&s,pair<S,T>&p){s>>p.first>>p.second;return s;}
template<class S,class T>ostream&operator<<(ostream&s,pair<S,T>&p){s<<p.first<<' '<<p.second<<'\n';return s;}
template<class T>istream&operator>>(istream&s,vector<T>&v){for(auto&i:v)s>>i;return s;}
template<class T>ostream&operator<<(ostream&s,vector<T>&v){for(int i=0;i<(int)v.size();i++)s<<v[i]<<" \n"[i==(int)v.size()-1];return s;}
const int dxy[5]={0,1,0,-1,0};
const int dx[8]={0,1,0,-1,1,1,-1,-1};
const int dy[8]={1,0,-1,0,1,-1,1,-1};
#define nl '\n'
#define sp ' '
const int inf = (1<<30)-(1<<15);
const ll INF = 1LL<<61;
const ll mod = 998244353;
const ll MOD = 1000000007;
const ld EPS = 1e-9;
const ld PI = acos(-1);

void IO() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout<<fixed<<setprecision(30);
}

void solve();
// poe

int main() { IO();
    int T=1;
    cin >> T;
    while (T--) solve();
}

void solve() {
	int n; cin >> n;
	vi a(n); cin >> a;
	range(i, a) if (i == 0) { cout << 0 << nl; return; }
	bool p=false, m=false;
	range(i, a) {
		if (0 < i) p = true;
		else m = true;
	}
	if (p && m) {
		int P=inf, M=-inf;
		range(i, a) {
			if (0 < i) chmin(P, i);
			else chmax(M, i);
		}
		cout << 1LL * P * M << nl;
	} else {
		cout << 1LL * Min(a) * Max(a) << nl;
	}
}