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 homework {

    public static void main(String[] args){

        // System.out.println(a);
        Scanner sc = new Scanner(System.in);

        int x = sc.nextInt();

        for (int i = 1; i <= x; i++){

            int a = i;
            //System.out.println(a);
            for (int j = 1; j <= x; j++){

                int b = j;
                //System.out.println(b);
                if ((a <= x) && (b <= x) && ((a*b) > x) && ((a/b) < x) && (a%b == 0)) {
                    System.out.println(a + " " + b);
                    System.exit(0);
                }
            }

        }
        System.out.println(-1);
    }
}