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.
c=int(input())
a=input().split()
p=a
q=0
for i in range(len(a)):
    s=0
    for k in range(len(a)):
        if (int(a[k])%int(a[i])!=0):
            break
        else:
            s+=1
    if s==len(a):
        q=1
        break
if q==1:
    print(a[i])
else:
    print('-1')