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:
/* package whatever; // don't place package name! */

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

/* Name of the class has to be "Main" only if the class is public. */
public class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner in=new Scanner(System.in);
		int x=in.nextInt(),i,j;
		boolean b=false;
		for(i=1;i<=x;i++)
		{
			for(j=i;j<=x;j++)
			{
				if(j%i==0 && i*j>x && j/i<x)
				{
					b=true;
					System.out.println(j+" "+i);
					return ;
				}
			}
		}
		System.out.println(-1);
	}
}