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:
// package c524d2;

import java.util.Scanner;

public class A1 {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		boolean f = false;
		a : for(int i = 1 ; i <= n ; i++){
			for(int j = 1 ; j <= i ; j++){
				if(i%j==0 && i*j> n && i/j < n ){
					System.out.print(i + " " + j);
					f=true;
					break a;
				}
			}
		}
		if(f==false){
			System.out.println("-1");
		}
	}
}