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.
n = input()
li = list(map(int,input().split()))
m = min(li)
for item in li:
    if item % m != 0:
        m=-1
        break;
print (m)