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())

arr = list(map(int, input().split()))

gc = 0
isOne = False

for i in range(n):
    if arr[i] == 1:
        isOne = True
        break
    gc = math.gcd(gc, arr[i])


if isOne:
    print(1)
elif gc == 1:
    print(-1)
else:
    ans = -1
    for i in arr:
        if gc%i == 0:
            ans = i
            break
    print(ans)


