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 A {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner s = new Scanner(System.in);
		int x = s.nextInt();
		boolean f = false;
		for(int i=1;i<=x;i++)
		{
			for(int j=1;j<=i;j++)
			{
				if(i%j==0)
				{
					if(((i*j)>x)&&((i/j)<x))
					{
						System.out.println(i+" "+j);
						i=x+1;
						f = true;
						return;
					}
						
				}
			}
		}
		if(!f)
		{
			System.out.println(-1);
		}
	}

}