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.lang.annotation.*;
import java.util.*;
import java.io.*;
public class Construction {

	public static void main(String[] args)throws Exception {
		// TODO Auto-generated method stub
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		
			int num=Integer.parseInt(br.readLine());
			int t=0;boolean flat=true;
		for(int s=1;s<=num;s++) {
			for(t=1;t<num;t++) {
				if(t%s==0 && s/t<num && s*t>num) {
					
						
						System.out.print(t+" "+s+" ");
						System.exit(0);
						
						
						
					
				}
				
			}
			
			
		}
			if(num==2)System.out.print("2 2");
			else
			System.out.print("-1");
		
		
		   
		
		
 
	}

}