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.Scanner;
public class contest {
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		boolean t = true;
		for(int a=1;a<=x && t;a++) {
			for(int b=1;b<=x && t;b++) {
				if(a*b>x && a/(double)b<x && a%b==0) {
					System.out.println(a + " " + b);
					t = false;
				}
			}
		}
		if(t)
			System.out.println(-1);
}
}