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:
num = int(raw_input())

def find(num):
  for i in range(1, num + 1):
    for j in range(1, num + 1):
     if i % j == 0 and (i * j) > num and (i / j) < num:
      return (i,j)
  return -1

res = find(num)

if res == -1:
    print res
else:
    print res[0],res[1]