$Gogi$, $Tapu$ and $Sonu$ are the elite members of $Tapu$ $Sena$. $Gogi$ is always stoned and asks absurd questions, But this time he asked a question which seems to be very serious and interesting. $Tapu$ wants to solve this question to impress $Sonu$. He  gave an array of length N to $Tapu$, $Tapu$ can perform the following operations exactly once:
- Remove any subarray from the given array given the resulting array formed after the removal is non-empty.    
- Reverse the whole array.
Remember you can’t shuffle the elements of the array.
Tapu needs to find out the maximum possible GCD of all the numbers in the array after applying the given operations exactly once. Tapu is very weak at programming, he wants you to solve this problem so that he can impress $Sonu$.

-----Input:-----
- The first line contains $T$, the number of test cases.
- For each test case
-FIrst line contains $N$.
- Last line contains $N$ numbers of the array. 

-----Output:-----
A single integer in a new line, maximum possible GCD. 

-----Constraints-----
- $1 \leq T \leq 10^2$
- $1 \leq N \leq 10^4$
- $1 \leq a[i] \leq 10^9$

Summation of N for all testcases is less than $10^6$ 

-----Sample Input 1:-----
1
1
2

-----Sample Output 1:-----
2

Source: codechef | Difficulty: UNKNOWN_DIFFICULTY


Solutions:
try:
	t = int(input())
	for _ in range(t):
		n = int(input())
		a = list(map(int, input().split()))
		gcd = max(a[0], a[-1])
		print(gcd)
except EOFError:
	pass


t = int(input())
for i in range(t):
	n = int(input())
	a = [int(x) for x in input().split()]
	print(max(a[0], a[-1]))


from math import gcd
st = ''

def func(n, l1):
	if n == 1:
		return l1[0]
	elif n == 2:
		return gcd(l1[0], l1[1])
	p = l1[0]
	m = p
	for i in range(1, n):
		g = gcd(p, l1[i])
		m = max(m, g)
		p = g
	p = l1[-1]
	m = max(m, p)
	for i in range(n - 2, 0, -1):
		g = gcd(l1[i], p)
		m = max(m, g)
		p = g
	return m
for _ in range(int(input())):
	n = int(input())
	l1 = list(map(int, input().split()))
	st += str(func(n, l1)) + '\n'
print(st)


t = int(input())
for _ in range(t):
	n = int(input())
	arr = list(map(int, input().strip().split()))
	print(max(arr[0], arr[-1]))


from sys import stdin, stdout
import math
from itertools import permutations, combinations
from collections import defaultdict

def L():
	return list(map(int, stdin.readline().split()))

def In():
	return list(map(int, stdin.readline().split()))

def I():
	return int(stdin.readline())
P = 1000000007
for t in range(I()):
	n = I()
	arr = L()
	if arr[0] >= arr[n - 1]:
		print(arr[0])
	else:
		print(arr[n - 1])


for i in range(int(input())):
	n = input()
	l = list(map(int, input().split()))
	print(max(l[0], l[-1]))


t = int(input())
for i in range(t):
	n = int(input())
	l = list(map(int, input().split()))
	e = 1
	for j in l:
		if j % e == 0:
			e = j
		else:
			break
	l.reverse()
	f = 1
	for s in l:
		if s % f == 0:
			f = s
		else:
			break
	if e > f:
		f = e
	print(f)


import math
t = int(input())
for t1 in range(0, t):
	n = int(input())
	l = list(map(int, input().split()))
	if n == 1:
		print(*l)
	else:
		x = l[0]
		y = l[-1]
		l1 = []
		l2 = []
		for i in range(0, n):
			x = math.gcd(x, l[i])
			l1.append(x)
			if x == 1:
				break
		for j in range(n - 1, -1, -1):
			y = math.gcd(y, l[j])
			l2.append(y)
			if y == 1:
				break
		print(max(max(l1), max(l2)))


from math import gcd
t = int(input())
for _ in range(t):
	n = int(input())
	l = list(map(int, input().split()))
	print(max(l[0], l[n - 1]))


def gcd(a, b):
	if b == 0:
		return a
	else:
		return gcd(b, a % b)
t = int(input())
for u in range(t):
	n = int(input())
	a = list(map(int, input().split()))
	ans = a[0]
	for i in a:
		h = gcd(ans, i)
		if h > ans:
			ans = h
		else:
			break
	a.reverse()
	ans2 = a[0]
	for i in a:
		h = gcd(ans2, i)
		if h > ans:
			ans2 = h
		else:
			break
	ans3 = gcd(ans, ans2)
	print(max(ans, max(ans2, ans3)))


t = int(input())
for _ in range(t):
	n = int(input())
	a = list(map(int, input().split()))
	if a[0] > a[n - 1]:
		print(a[0])
	else:
		print(a[n - 1])


t = int(input())
for _ in range(t):
	n = int(input())
	f = [int(i) for i in input().split()]
	r = max(f[0], f[-1])
	print(r)


import math
T = int(input())
for _ in range(T):
	N = int(input())
	ar = input().split()
	m = int(ar[0])
	if int(ar[N - 1]) > m:
		m = int(ar[N - 1])
	print(m)


a = int(input())
for i in range(0, a):
	b = int(input())
	c = list(map(int, input().split()))
	if c[0] > c[len(c) - 1]:
		print(c[0])
	else:
		print(c[len(c) - 1])


t = int(input())
for i in range(0, t):
	n = int(input())
	l = list(map(int, input().split()))
	if n == 1:
		print(l[0])
	else:
		print(max(l[n - 1], l[0]))


for _ in range(int(input())):
	n = int(input())
	a = list(map(int, input().split()))
	print(max(a[0], a[n - 1]))


t = int(input())
for _ in range(t):
	n = int(input())
	a = [int(x) for x in input().split()]
	if a[0] > a[-1]:
		print(a[0])
	else:
		print(a[-1])


from sys import stdin, stdout
import math
import heapq
t = 1

def aint():
	return int(input().strip())

def lint():
	return list(map(int, input().split()))

def fint():
	return list(map(int, stdin.readline().split()))

def main():
	n = aint()
	l = lint()
	pre = [l[0]]
	suff = [l[-1]]
	for i in range(1, n):
		pre.append(math.gcd(pre[-1], l[i]))
	for i in range(n - 2, -1, -1):
		suff.append(math.gcd(suff[-1], l[i]))
	print(max(max(pre), max(suff)))
t = aint()
for i in range(t):
	main()