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

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);
        int x=in.nextInt();
        boolean check=true;
        for(int i=1;i<=x;i++){
            for(int j=1;j<=x;j++){
                if(i%j==0&&i/j<x&&i*j>x){
                    out.println(i+" "+j);check=false;break;
                }
            }if(!check)break;
        }
        if(check)out.println(-1);
        out.flush();
        out.close();
    }
     static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }
         public InputReader(FileReader f) {
        reader = new BufferedReader(f);
        }
        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 int nextInt() {
            return Integer.parseInt(next());
        }
        
        public long nextLong() {
            return Long.parseLong(next());
        }

        public String nextLine(){
            try{
            return reader.readLine();
            }catch(IOException e){
                throw new RuntimeException(e);
            }
        }
        
        double nextDouble(){
            try{
           return Double.parseDouble(next());
          }catch(Exception e){
                throw new RuntimeException(e);
            }
    }
    
    }
}