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 Construct {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        for(int a = 1; a<=x; a++) {
            for(int b = a; b<=x; b++ ) {
                if(a%b!=0) continue;
                if(a*b<=x) continue;
                if(a/b>=x) continue;
                System.out.println(""+a+ " "+b);
                return;
            }
        }
        System.out.println("-1");
    }
}