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 sys
input=sys.stdin.readline
def GCD(a,b):
    while b!= 0:
        a,b =b,a%b
    return a     
t=int(input())
ls=[int(i) for i in input().split()]
hash_map=dict()
for i in range(len(ls)):
    hash_map[ls[i]]=i
for i in range(len(ls)-1):
    gcd=GCD(ls[i],ls[i+1])
print(gcd) if hash_map.get(gcd)!=None else print(-1)
