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 A {
    static Scanner s = new Scanner(System.in);
    public static void main(String[] args) {
        int x = s.nextInt();
        for (int i = 1; i <= x; i++) {
            for (int j = 1; j <= x; j++) {
                if (i * j > x && i % j == 0 && i / j < x) {
                    System.out.println(i + " " + j);
                    return;
                }
            }
        }
        System.out.println(-1);
    }
}