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;
import java.util.Arrays;

public class A1088{
    public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    int x = scan.nextInt();
    int[] arr = new int[x];
    for(int i = 1 ; i <= x; i ++){
        arr[i-1] = i;
    }
    int[] arr2 = new int[2];
    //System.out.println(Arrays.toString(arr));
    for(int i = 0; i < arr.length; i ++){
        for(int j = 0; j < arr.length; j ++){
            
            if(arr[j] % arr[i]  == 0 && arr[j] * arr[i] > x){
           
                if(arr[i]/arr[j] < x){
                    arr2[0] = arr[i];
                    arr2[1] = arr[j];
                
                }
            }
          
        }
    }
    if(arr2[1] == 0 || arr2[0] == 0 ){
        System.out.println("-1");
    }else{
    System.out.println(arr2[0] + " " + arr2[1]);
    }
    }
}