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 sys

n = int(input())

for j in range(int(n / 2), n+1):
  for i in range(int(j / 2) + 1, 0, -1):
    if j * i <= n or j / i >= n:
      continue
    if j % i == 0:
      print(j, i)
      sys.exit(0)


print(-1)