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.
# -*- coding: utf-8 -*-
"""
Created on Tue Oct 17 09:48:36 2023

@author: lakne
"""

n = int(input())
array = input().split()

array_set = list(set(array))

for i in range(len(array_set)):
    x = int(array_set[i])
    a = True
    for j in range(len(array)):
        if int(array[j]) % x != 0:
            a = False
            x = -1
    if a:
        print(x)
        break
if x == -1:
    print(x)