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

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
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);
        CF525d2_A solver = new CF525d2_A();
        solver.solve(1, in, out);
        out.close();
    }

    static class CF525d2_A {
        public void solve(int testNumber, InputReader in, PrintWriter out) {
            int n = in.nextInt();
            for (int i = 1; i <= n; i++) {
                for (int j = i; j <= n; j += i) {
                    if (i * j > n && (double) j / i < n) {
                        out.printf("%d %d\n", j, i);
                        return;
                    }
                }
            }
            out.println("-1");
        }

    }

    static class InputReader {
        private BufferedReader reader;
        private StringTokenizer tokenizer;
        public int numEmptyLines;
        private final int MAX_NUM_EMPTY_LINES = 2;

        public InputReader(InputStream inStream) {
            reader = new BufferedReader(new InputStreamReader(inStream));
            tokenizer = null;
            numEmptyLines = 0;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    String line = reader.readLine();
                    while (line == null) {
                        numEmptyLines++;
                        if (numEmptyLines == MAX_NUM_EMPTY_LINES) {
                            return null;
                        }
                    }
                    numEmptyLines = 0;
                    tokenizer = new StringTokenizer(line);
                } catch (IOException e) {
                    throw new RuntimeException("Input Error");
                }
            }
            return tokenizer.nextToken();
        }

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

    }
}