for _ in range(int(input())):
    n = int(input())
    A = list(map(int, input().split()))
    ma = mb = 0
    for a in A[1:]:
        if a == 0:
            continue
        ca = cb = 0
        t = len(str(a))
        while not a % 2:
            a //= 2
            ca += 1
        while not a % 5:
            a //= 5
            cb += 1
        ma = max(ma, t-ca)
        mb = max(mb, t-cb)
    print(pow(2, ma) * pow(5, mb))