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:
//package usaco.Problems;



import java.io.*;
import java.util.*;

public class problem1 {
	public static void main(String[] args) throws IOException {

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));

		//BufferedReader br = new BufferedReader(new FileReader("p1.in"));
		//PrintWriter pw = new PrintWriter(new FileWriter("p1.out"));
		int a = 0;
		p1 solver = new p1();
		solver.solve(br, pw);
	}

	static class p1 {
		public void solve(BufferedReader br, PrintWriter pw) throws IOException {
			//StringTokenizer st = new StringTokenizer(br.readLine());
			int x = Integer.parseInt(br.readLine());
			
			if(x == 1 || x == 0) {
				pw.println(-1);
				pw.close();
			}
			
			for(int i = 1; i <= x; i++) {
				for(int j = 1; j <= x; j++) {
					if((i%j == 0) && (j*i) > x && (i/j < x)) {
						pw.println(i + " " + j);
						pw.close();
					}
				}
			}
			

			
		}
	}
}