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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        AEhabAndAnotherConstructionProblem solver = new AEhabAndAnotherConstructionProblem();
        solver.solve(1, in, out);
        out.close();
    }

    static class AEhabAndAnotherConstructionProblem {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int x = in.nextInt();

            for (int i = 1; i <= x; i++) {
                for (int j = i; j <= x; j++) {
                    if ((j % i == 0) && (i * j > x) && (i / j < x)) {
                        out.println(j + " " + i);
                        return;
                    }
                }
            }

            out.println(-1);
        }

    }
}