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 Spoj {


    static long mod = (long)1e9+7;
    public static void main(String[] arg) {
        final Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        for(int i=2;i<=n; i++) {
            if(n%i == 0) {
                System.out.println(n + " " + i);
                return;
            }
        }
        System.out.println("-1");
    }
}