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.*;
import java.io.*;
import java.util.regex.*;
import java.math.BigInteger;


public class Main
{
	public static void main(String[] args)
	{
		try{
			BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
			Scanner scan = new Scanner(System.in);
			PrintWriter out = new PrintWriter(System.out);

			int input = scan.nextInt();
			if(input < 2){
				System.out.println("-1");
			}else if(input % 2 == 0){
				System.out.println(input + " " + 2);
			}else{
				System.out.println((input - 1) + " " + 2);
			}
		}
		catch(Exception e){
		}
	}
}