Ksusha is a beginner coder. Today she starts studying arrays. She has array a1, a2, ..., an, 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!

Input

The first line contains integer n (1 ≤ n ≤ 105), showing how many numbers the array has. The next line contains integers a1, a2, ..., an (1 ≤ ai ≤ 109) — the array elements.

Output

Print a single integer — the number from the array, such that all array elements are divisible by it. If such number doesn't exist, print -1.

If there are multiple answers, you are allowed to print any of them.

Examples

Input

3
2 2 4


Output

2


Input

5
2 1 3 1 6


Output

1


Input

3
2 3 5


Output

-1
n = int(raw_input())

arr = map(int,raw_input().split())

m = min(arr)

if 1 in arr:
    print 1
else:
    count = 0
    for i in arr:
        if i % m != 0:
            break
        elif i % m == 0:
            count += 1
    if count == len(arr):
        print m
        
    else:
        print -1

##for i in arr:
##    if i%m != 0:
##        b = Fa;se
##        break
##
##if b == True:
##    print m
##else:
##    print -1
##    
    
            
    
