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.
def gcd(a,b):
    if(a==0):
        return b
    return gcd(b%a,a)

def getfctrlist(a):
    F = [1,a]
    for i in range(2,int(a**0.5)+1):
        if(a%i==0):
            if(a//i==i):
                F.append(i)
            else:
                F.append(i);F.append(a//i)
    F.sort()
    return F

n = int(input())
A = list(map(int,input().split()))
a = A[0]
for i in range(1,n):
    a = gcd(a,A[i])
F = getfctrlist(a)
ans = -1
for i in A:
    if(i in F):
        ans = i
        break
print(ans)