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 b {
	static class FastReader 
	{ 
		BufferedReader br; 
		StringTokenizer st; 

		public FastReader() throws Exception
		{ 
			br = new BufferedReader(new
					InputStreamReader(System.in)); 
		} 

		String next() 
		{ 
			while (st == null || !st.hasMoreElements()) 
			{ 
				try
				{ 
					st = new StringTokenizer(br.readLine()); 
				} 
				catch (IOException e) 
				{ 
					e.printStackTrace(); 
				} 
			} 
			return st.nextToken(); 
		} 

		int nextInt() 
		{ 
			return Integer.parseInt(next()); 
		} 

		long nextLong() 
		{ 
			return Long.parseLong(next()); 
		} 

		double nextDouble() 
		{ 
			return Double.parseDouble(next()); 
		} 

		String nextLine() 
		{ 
			String str = ""; 
			try
			{ 
				str = br.readLine(); 
			} 
			catch (IOException e) 
			{ 
				e.printStackTrace(); 
			} 
			return str; 
		} 
		int[] readArray(int n) {
			int[] a = new int[n];
			for(int i = 0; i < n; i++) {
				a[i] = Integer.parseInt(next());
			}
			return a;
		}
		void debug(Object...args)
	    {
	        System.out.println(Arrays.deepToString(args));
	    }
	} 
	public static void main(String[] args) throws Exception {
		FastReader scan =new FastReader();
		PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
		int n = scan.nextInt();
		if(n == 1) {
			out.println(-1);
		}
		else {
			out.println(n+" "+n);
		}
		out.flush();
		
	}
}