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 codeForce2 {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int t = scan.nextInt();
		if(t==1) {
			System.out.println(-1);	
		}
		for(int c=0;c<=t;c++) {
			for(int l=c;l<=t;l++) {
				if(c*l>t&&(l%c==0)) {
					System.out.println(l+" "+c);
					return;
				}
			}	
			
		}
	}

}