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 cf525A{
	public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
         int x=n;
		if((n/2)%2==1){
          n = n/2+1;
		}
		else{
			n = n/2 +2;
		}
        
        if(n/2 < x && n*2 > x){
          System.out.println(n+" "+"2");
        }
		else{
			System.out.println(-1);
		}
	}
}