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 b>a:
		a=a+b
		b=a-b
		a=a-b
	if a%b==0:
		return b
	return gcd(b,a%b)
def solve(A):
	n=len(A)
	P=[A[0]] #prefix gcd 
	S=[A[-1]]*(n+1) #suffix gcd
	for i in range(1,n):
		P.append(gcd(P[-1],A[i]));
	for i in range(n-1,-1,-1):
		S[i]=gcd(S[i+1],A[i])
	
	for i in range(n):
		if gcd(S[i],P[i])==A[i]:
			return A[i]
	return -1;

n= input()
A=list(map(int,input().strip().split()))

print(solve(A))
		
	