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.*;
import java.io.*;

public class Ehabandanotherconstructionproblem {

	// https://codeforces.com/contest/1088/problem/A
	
	public static void main(String[] args) throws IOException, FileNotFoundException {
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		//BufferedReader in = new BufferedReader(new FileReader("Ehabandanotherconstructionproblem"));

		int n = Integer.parseInt(in.readLine());
		if (n == 1) System.out.println(-1);
		else {
			System.out.println(n + " " + (n));
		}

	}

}