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.math.BigInteger;
import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        int b=n;
        int a=n;
        //System.out.println(a+" "+b);
        while(true){
            if(1<=a && b<=n && a*b>n && a/b<n ){
                System.out.println(a+" "+b);
                break;
            }
            if (b<0){
                System.out.println(-1);
                break;
            }
            b--;
            a++;

        }

    }
}