def product(l):
    if l == []:
        return 1
    return l[0]*product(l[1:])


def once():
    input()
    ai = [int(i) for i in input().split()]

    ai_p = [a for a in ai if a > 0]
    ai_n = [a for a in ai if a < 0]
    contains0 = (0 in ai)

    ai_p.sort(reverse=True)
    ai_n.sort()

    if ai_p == []: # all neg or null
        if contains0:
            return 0
        return product(ai_n[-5:])

    elif len(ai_n)+len(ai_p) < 5:
        return product(ai)
    elif len(ai_n)+len(ai_p) == 5:
        p = product(ai_n)*product(ai_p)
        if p < 0 and contains0:
            return 0
        return p
    else:
        # selected = [ai_p[0]]
        i_n = 0
        i_p = 1
        prod = ai_p[0]

        for _ in range(2):
            if i_n + 2 > len(ai_n) and i_p + 2 <= len(ai_p):
                prod *= ai_p[i_p]*ai_p[i_p+1]
                # selected.append(ai_p[i_p])
                # selected.append(ai_p[i_p+1])
                i_p+=2
            elif i_p + 2 > len(ai_p) and i_n + 2 <= len(ai_n):
                prod *= ai_n[i_n]*ai_n[i_n+1]
                # selected.append(ai_n[i_n])
                # selected.append(ai_n[i_n+1])
                i_n+=2
            elif i_p +1 == len(ai_p) and i_n+1 == len(ai_n):
                prod *= ai_p[-1]*ai_n[-1]
            else:
                pp = ai_p[i_p]*ai_p[i_p+1]
                pn = ai_n[i_n]*ai_n[i_n+1]

                if pp > pn:
                    prod *= pp
                    # selected.append(ai_p[i_p])
                    # selected.append(ai_p[i_p+1])
                    i_p += 2
                else:
                    prod *= pn
                    # selected.append(ai_n[i_n])
                    # selected.append(ai_n[i_n+1])
                    i_n += 2
        return prod


def main():
    count = int(input())

    for _ in range(count):
        print(once())
        


main()