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.io.*;
import java.util.*;

public class cf5
{
	public static void main(String args[])

	{

		Scanner s=new Scanner(System.in);


		int x=s.nextInt();

		int a[]=new int[x];

		for(int i=0;i<x;i++)
		{
			a[i]=i+1;
		}

		int flag=0;


		for(int i=0;i<x;i++)
		{
			for(int j=0;j<x;j++)
			{

				if((a[i]%a[j]==0)&&((a[i]*a[j])>x)&&((a[i]/a[j])<x))
				{		

					System.out.println(a[i]+" "+a[j]);

					System.exit(0);


				
				}
			}
		}


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



	}
}