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 JAVA):

Solution:
/*                 _____                                                             ___
    /\      /\    |     | |   |    /\       /\      /\       /\      /\       /\    |   \     محمد أبوحسن*
   /  \    /  \   |     | |___|   /__\     /  \    /  \     /  \    /  \     /__\   |    \
  /    \  /    \  |     | |   |  /    \   /    \  /    \   /    \  /    \   /    \  |    /
 /      \/      \ |_____| |   | /      \ /      \/      \ /      \/      \ /      \ |___/
*/
import java.util.*;
public class Mohammad {
    public static void main(String[] args) {
        Scanner sc =new Scanner(System.in);
        int n = sc.nextInt();
        if(n == 1)
            System.out.println(-1);
        else
            System.out.println(n%2 == 0 ? n + " " + 2 : n-1 + " " + 2);
    }
}