#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
#define M 100009
#define INF 1e18-1
int main()
{
    int t;
    scanf("%d", &t);
    while(t--)
    {
        int n;
        scanf("%d", &n);
        long long ans = 1;
        long long maxx = -INF;
        bool ok = false;
        int cnt = 0,cntf = 0;
        for(int i = 0;i < n;i++)
        {
            
            long long a;
            scanf("%lld", &a);
            if (!a) cnt++;
            if(a != 0)
            {
                ans *= a;
                ok = true;
            }
            if(a < 0) {maxx = max(a,maxx);cntf++;}
        }
        if (cnt + cntf == n && cntf == 1) {
            if (cnt) cout << 0 << endl;
            else {
                cout << maxx << endl;
            }
            continue;
        }
        if(ans < 0) ans /= maxx;
        if(ok) cout << ans << endl;
        else cout << 0 << endl;
    }
    return 0;
}