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 MyClass {
    public static void main(String args[]) {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int x = 0;
        int y = 0;
        for(int i = 1; i <= a; i++){
            for(int j = 1; j <= a; j++){
                if(check(i, j, a)){
                    System.out.println(i + " " + j);
                    return;
                }
            }   
        }
        System.out.println(-1);
    }
    
    static boolean check(int a, int b, int n) {
        return (a % b == 0) &&(a*b > n) && (a/b < n);
    }
}