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.io.*;
import java.util.*;
public class A525 {

	public static void main(String[] args)throws Exception {
		BufferedReader f = new BufferedReader(new InputStreamReader(System.in));
		
		int N = Integer.parseInt(f.readLine());
		
		if(N == 1) {
			System.out.println(-1);
		}
		else {
			System.out.println(N + " " + N);
		}
	}

}