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:
from math import ceil

def ii():
  return int(input())
def ss():
  return [x for x in input()]
def si():
  return [int(x) for x in input().split()]
def mi():
  return map(int, input().split())

a = ii()
if a != 1:
  print(a, a)
else:
  print(-1)