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:

import static java.lang.System.exit;
import java.util.*;

public class Main {

    public static void main(String args[]) {
        LinkedList permutation = new LinkedList();

        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        if (n == 1) {
            System.out.println(-1);
            exit(0);
        }
        
        
        System.out.println(n+" "+n);

    }

}