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:
x = int(input())
flag = False
for b in range(1, x + 1):
  m = 1
  # Iterate only on the values t of a that b divides
  while b*m <= x and m < x:
    a = b*m
    if a*b > x:
      flag = True
      print(a, b)
      break
    m += 1
  if flag:
    break
if not flag:
  print(-1)