for _ in range(int(input())):
	n=int(input())
	a=list(map(int,input().split()))
	x=0 
	y=0
	for i in range(1,n):
		if a[i]>0:
			A=len(str(a[i]))
			B=len(str(a[i]))
			while a[i]%2==0 and A>0:
				A-=1 
				a[i]//=2 
			while a[i]%5==0 and B>0:
				B-=1 
				a[i]//=5 
			x=max(x,A)
			y=max(y,B)
	print(2**x*5**y)