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:
//*********************************
//  Ehab.java       Author: Patrick
//
//  Finds two integers that meet
//  a set of conditions
//*********************************

import java.util.Scanner;

public class Ehab
{
    public static void main(String[] args)
    {
        Scanner scan = new Scanner(System.in);
        int x = scan.nextInt();
        int a, b;
        boolean pair = false;

        while (!pair)
        {
            for (int i = 1; i <= x; i++) {
                for (int y = i; y <= x; y++) {
                    if (y % i == 0 && y * i > x && y / i < x) {
                        a = i;
                        b = y;
                        System.out.print(b + " " + a);
                        pair = true;
                    }   if (pair)
                            break;
                }   if (pair)
                        break;
            }   if (!pair)
                {
                    System.out.print(-1);
                    pair = true;
                }
        }
    }
}