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 EhabConstruction {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		getResult(x);
		sc.close();
	}
	
	static void getResult(int x) {
		for(int a = 1; a<=x; a++) {
			for(int b = 1; b<=x; b++) {
				if(valid(a, b, x)) {
					System.out.println(a + " " + b);
					return;
				}
			}
		}
		System.out.println("-1");
		return;
	}

	static boolean valid(int a, int b, int x) {
		if(a%b!=0) {
			return false;
		}
		if(a*b<=x) {
			return false;
		}
		if(a/b>=x) {
			return false;
		}
		return true;
	}
	
}