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

x=int(input())

for i in range(x):
  a=i+1
  for j in range(x):
    b= j+1
    if((a%b==0)and((a*b)>x)and((a/b)<x)):
      print(a,b)
      sys.exit(0)

print("-1")