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.*;

public class Main {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		int x = scanner.nextInt();
		boolean found = false;
		int a = 0;
		int b = 0;
		for (a = 1; a <= x; ++a)
		{
//			a%b==0
			for (b = 1; b <= x; b++)
			{
				if (a % b == 0 && a * b > x && a < x * b)
				{
					found = true;
					break;
				}
			}
			if (found)
				break;
		}
		if (found)
		{
			System.out.print(a + " " + b);
		}
		else
			System.out.print("-1");
		scanner.close();
	} // end main

}