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.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;


public class Main {
	public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(1, in, out);
        out.close();
    }

	static class P implements Comparable<P> {

		int a;
		int b;
		
		@Override
		public int compareTo(P arg0) {
			if(arg0.b < this.b) return 1;
			else return -1;
		}
	}
	
	static class Task {
		
		public void solve(int testNumber, InputReader in, PrintWriter out) {
        	int n = in.nextInt();
        	if(n==1) out.println("-1");
        	else {
        		int i;
        		for(i=2;i<=n;i++) {
        			if(i*i>n) {
        				out.print(i);
         				out.print(" ");
        				out.println(i);
        				break;
        			}
        		}
        		if(i>n) out.println("-1");
        	}
        }
    }
	static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }
        public long nextLong() {
            return Long.parseLong(next());
        }
        
        public int nextInt() {
            return Integer.parseInt(next());
        }

    }
}