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.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.StringTokenizer;
public class A1 {


public static void A(BufferedReader br) throws IOException
{	
		
	String s= br.readLine();
	StringTokenizer st=new StringTokenizer(s);
	int n= Integer.parseInt(st.nextToken());
	int a,b=-1;
	if(n%2==0)
	{	
		a=n;
		b=2;
	}
	else
	{
		a=n-1;
		b=2;
	}
	if(n==1)
	{
		a=-1;
		b=-1;
		System.out.println(a);
	}
	else
	{
		System.out.println(a+" "+b);
	}
}

		
	
public static void main(String[]args) throws IOException
{
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	A(br);
	
}
	
}