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.*;

public class ProblemA {

	public static void main(String[] args) {
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
		try {
			int n=Integer.parseInt(br.readLine());
			if(n==1) {
				bw.write("-1");
			}
			else {
				int res = n - n % 2;
				bw.write(String.valueOf(res) + " " + "2");
			}
			bw.flush();
			bw.close();
			br.close();
		} catch (NumberFormatException | IOException e) {
			e.printStackTrace();
		}
	}
}