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:
/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author Леван
 */
import java.util.Scanner;

/**
 *
 * @author Леван
 */
public class EhabIKontr {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int[] result = find(a);
        if(result[0]==-1){
            System.out.print(-1);
        }
        else{
            System.out.print(result[0]+" "+result[1]);
        }
    }
    
    static int[] find(int a){
        for(int i = 1 ; i <= a ; i++){
            for(int b = 1; b <= i; b++){
                if(i%b==0 && i*b>a && i/b < a){
                    int[] result = {i,b};
                    return result;
                }
            }
        }
        int[] result = {-1,-1};
        return result;
    }
    
}