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 find_gcd(x, y):
    while(y):
        x, y = y, x % y 
    return x  
n=int(input())
l = list(map(int,input().split())) 
num1 = l[0] 
num2 = l[1] 
gcd = find_gcd(num1, num2) 
for i in range(2, len(l)): 
    gcd = find_gcd(gcd, l[i]) 
if gcd in l:
    print(gcd)
else:
    print(-1)