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.*;
public class Ehab1
{
	int x;
	public static void main(String args[])
	{
		int flagi=0;
		Ehab1 ehab=new Ehab1();
		Scanner s=new Scanner(System.in);
		ehab.x=s.nextInt();
		for(int i=1;i<=ehab.x;i++)
		{
			flagi=0;
			for(int j=1;j<=ehab.x;j++)
			{
				if(j%i==0&&j*i>ehab.x&&j/i<ehab.x)
				{
					System.out.printf("%d %d ",j,i);
					flagi=1;
					break;
				}
			}
			if(flagi==1)
				break;
		}
		if(flagi==0)
			System.out.println("-1");
	}
}