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:
/**
 *
 * @author alex
 */

import java.util.Scanner;

public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int EntradaInt = in.nextInt();
        for (int primero = 1; primero <= EntradaInt; primero++) {
            for (int segundo = 1; segundo <= EntradaInt; segundo++) {
                if ((primero%segundo==0)&&(primero*segundo>EntradaInt)&&(primero/segundo<EntradaInt)) {
                    System.out.println(primero+" "+segundo);
                    System.exit(0);
                }
            }
        }
        System.out.println(-1);
    }
    
}