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 java.util.Scanner;

public class solution_1
{
    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        int q = sc.nextInt();
        if(q>1){
            if(q%2 == 1)
                q--;
            System.out.print(q);
            System.out.println(" 2");
        }
        else{
            System.out.println("-1");
        }
    }
}