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.util.Scanner;
public class Codeforces1{
	private static int a,b,x,tests,flag;
	private static Scanner in;
	public static void main(String[] args){
		in=new Scanner(System.in);
		//tests=in.nextInt();
		
			x=in.nextInt();
			flag=0;
			for( a=1;a<=x;a++){
				for( b=1; b<=x;b++){
					if((a%b) ==0 && (a/b) < x && (a*b ) > x  ){
						System.out.println(a+" "+b);
						flag=1;
						break;
					}
				}
				if(flag == 1)
					break;
			}
			if(a== (x+1))
				System.out.println("-1");
		
	}
}