Ksusha is a beginner coder. Today she starts studying arrays. She has array *a*<sub class="lower-index">1</sub>, *a*<sub class="lower-index">2</sub>, ..., *a*<sub class="lower-index">*n*</sub>, consisting of *n* positive integers.

Her university teacher gave her a task. Find such number in the array, that all array elements are divisible by it. Help her and find the number!
The first line contains integer *n* (1 ≤ *n* ≤ 10<sup class="upper-index">5</sup>), showing how many numbers the array has. The next line contains integers *a*<sub class="lower-index">1</sub>, *a*<sub class="lower-index">2</sub>, ..., *a*<sub class="lower-index">*n*</sub> (1 ≤ *a*<sub class="lower-index">*i*</sub> ≤ 10<sup class="upper-index">9</sup>) — the array elements.
def common_array_divisor(nums):
    if len(nums) == 0:
        return -1
    
    n = len(nums)
    nums.sort()
    min_num = num[0]
    
    for i in range(n):
        if nums[i] % min_num != 0:
            return -1
        
    return min_num
       
t = int(input())
#t = 1
for _ in range(t):
    #a = list(map(int,input().split()))
    n = int(input())
    nums = list(map(int,input().split()))
    print(common_array_divisor(nums))
    
