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.*;


public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner scan = new Scanner(System.in);
        int x = scan.nextInt();
        int a=0;
        int b=0;
        for (int i=1; i<=x;i++){
            ArrayList<Integer> multiplos = new ArrayList<Integer>();
            int aux=1;
            while((aux*i)<=x){
                multiplos.add(i*aux);
                aux++;
            }
            
            
            while(!multiplos.isEmpty()){
                int a1 = multiplos.remove(0);
                int b1 = i;
                if((a1*b1)>x && (a1/b1)<x){
                    a=a1;
                    b=b1;
                    break;
                }
            }
            
            if(a!=0 && b!=0)
                break;
        }
        if(a!=0 && b!=0)
            System.out.print(a +" "+ b);
        else
            System.out.print("-1");
    }
}