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.*;

public class problemA {
    private static final BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
//    private static final Scanner in = new Scanner(System.in);

    public static void main(String[] args) throws IOException {
        int t = 1;
//        t = Integer.parseInt(in.readLine());
//        t = in.nextInt();
        while (t != 0) {
            play();
            t--;
        }
    }

    public static void play() throws IOException {
        int n = Integer.parseInt(in.readLine());
        System.out.println(n == 1 ? -1 : n + " " + n);
    }
}