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 EhabAndAnotherConstructionProblem
{
    public static void main( String [] args )
    {
        Scanner input = new Scanner( System.in );

        int x = input.nextInt();

        int a = x - 1, b = x - 1;

        if( x == 1 )
            System.out.println( -1 );
        else if( x == 2 )
            System.out.println( 2 + " " + 2 );
        else
        {
            if( a % b == 0 && a * b > x && a / b < x )
                System.out.println( a + " " + b );
            else
            {
                if ( a % b == 0 && a * b > x && a / b < x )
                {
                    do {
                        a = x - 1;
                        b = x - 1;
                    } while ( a % b == 0 && a * b > x && a / b < x );
                }
                else
                    System.out.println( -1 );
            }
        }
    }
}