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 p1088A {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);

		int n = scan.nextInt();

		for (int a = 1; a <= n; a++) {

			for (int b = 1; b <= n; b++) {

				if (a % b == 0 && (a / b < n) && a * b > n) {

					System.out.print(a + " ");
					System.out.println(b);
					return;

				}

			}

		}
		System.out.println(-1);
	}
}