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 PYTHON3):

Solution:
import math

var_x = int(input())

if(var_x != 1):
  if ( ( math.floor( var_x/2 ) +1 ) % 2 == 0 ):
        print( str ( math.floor ( var_x/2 )+1 ) +  " 2" ) 
  else:
        print( str(math.floor( var_x/2 )+2 ) + " 2" )
else:
    print( -1 )