import math

arr = [[15,20],[36,48],[12,7],[121,44],[39,65]]
list = []
answer = 0

a1 = 0
a2 = 0
a3 = 0
a4 = 0
a5 = 0

    
a1 = math.gcd(arr[0][0],arr[0][1])
a2 = math.gcd(arr[1][0],arr[1][1])
a3 = math.gcd(arr[2][0],arr[2][1])
a4 = math.gcd(arr[3][0],arr[3][1])
a5 = math.gcd(arr[4][0],arr[4][1])

list.append(a1)
list.append(a2)
list.append(a3)
list.append(a4)
list.append(a5)

answer = max(list)
print(answer)