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.*;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scan = new Scanner(System.in);
		int x = scan.nextInt();
		for (int a = 1; a <= x; a++) {
			for (int b = 1; b <= x; b++) {
				if ((a % b == 0) && (a * b > x) && (a / b < x)) {
					System.out.print(a + " " + b);
					System.exit(0);
				}
			}
		}
		System.out.print(-1);
		scan.close();
	}

}