import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################

"""
a +  b / 10 ** (len(b))

"""
def f(x, b):
    e = 0
    while x % b == 0:
        x //= b
        e += 1

    return e

for _ in range(ni()):
    n = ni()
    a = na()
    z2 = 0
    z5 = 0
    for i in range(1, n):
        if a[i] == 0:
            continue
        z2 = max(z2, len(str(a[i])) - f(a[i], 2))
        z5 = max(z5, len(str(a[i])) - f(a[i], 5))
    
    print(2 ** z2 * 5 ** z5)