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 JavaApplicationM{
public static void main(String[] args) {
Scanner in=new Scanner(System.in);

//----------------------------------------------
long t=in.nextInt(),z,x;

for(int y=1;y<=t;y++)
{
    z=y;
    x=z*2;
    if(t==2||t==3){System.out.println(2+" "+2);break;}
    if(x>t){System.out.println(-1);break;}
    
    if(z*x>t)
    {
        if(z/x<t)
        {
            System.out.println(x+" "+z);
            break;
        }
    }
    
}


 // 
}}