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.
import math
n = int(input())
a = (input().split(' '))
a1 = int(a[0])
a2 = int(a[1])
f = 0
for x in range(n-2): 
    a1 = math.gcd(int(a1), int(a2))
    if x == 1:
        f = 1
    if n <= 3:
        break
    a2 = a[x+2]
if (a1 == 1 and f == 1) or a1 > 1:
    print(a1)
else:
    print(-1)
 				  		 	   			  		 						