Problem: Given an integer x, find 2 integers a and b such that: 

  * 1 ≤ a,b ≤ x 
  * b divides a (a is divisible by b). 
  * a ⋅ b>x. 
  * a/b<x. 

Input

The only line contains the integer x (1 ≤ x ≤ 100).

Output

You should output two integers a and b, satisfying the given conditions, separated by a space. If no pair of integers satisfy the conditions above, print "-1" (without quotes).

Examples

Input

10


Output

6 3

Input

1


Output

-1

Solution (in PYTHON):

Solution:
def is_odd(num):
   if num % 2 == 0:
      return False
   return True

value = input()

if value <= 1:
   print -1
else:
   if value % 2 == 0:
      if is_odd(value / 2):
         print "%d %d" % ((value / 2) + 1, 2)
      else:
         print "%d %d" % ((value / 2) + 2, 2)
   else:
      if not is_odd(value / 2):
         print "%d %d" % ((value / 2) + 2, 2)
      else:
         print "%d %d" % ((value / 2) + 1, 2)