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 CFEhab{
	public static void main(String[] args) {
		try{
			BufferedReader read = new BufferedReader(new InputStreamReader(System.in));
			int x = Integer.parseInt(read.readLine());
			int d = x/2;
			int l = d/2;
			boolean flag = true;
			l++;
			d= l*2;
			if(d<=x){
				flag = false;
				System.out.println(d+" "+"2");
			} 
			if (flag) {
				System.out.println(-1);
			}
		}catch(Exception e){

		}
	}
}