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 testing{

	public static void main(String[] args){
		
		Scanner scanner = new Scanner(System.in);
		int x = scanner.nextInt();
		
		boolean b = false;
		for(int i = 1 ; i <= x ; ++i) {
			for(int j = i; j <= x; j += i) {
				if(i * j > x && j < x * i) {
					System.out.println(j + " " + i);
					b = !b;
					break;
				}
			}
			if(b) break;
		}
		
		

		
		if(!b) System.out.println(-1);
	}

}