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 EhabConstruct {
	public static void main(String[] args) {

		Scanner in = new Scanner(System.in);
		int x = in.nextInt(), a, b;
		in.close();
		String o = "-1";

		outer: for (a = 1; a <= x; a++) {
			for (b = 1; b <= x; b++) {

				if (a % b == 0 && a * b > x && a / b < x) {
					o = a + " " + b;
					break outer;
				}
			}
		}
		System.out.println(o);
	}
}