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.util.Arrays;
import java.util.StringTokenizer;

public class CF525A {
    private static InputReader in = new InputReader(System.in);

    public static void main(String[] args) {
        int x = in.nextInt();
        for (int a = 1; a <= x; a++) {
            for (int b = 1; b <= x; b++) {
                if (a % b != 0) {
                    continue;
                }
                if (a * b <= x) {
                    continue;
                }
                if (a / b >= x) {
                    continue;
                }
                System.out.println(a + " " + b);
                return;
            }
        }
        System.out.println(-1);
    }

    static private void print(Object... o) {
        boolean test = false;
        if (test) {
            String s = Arrays.deepToString(o);
            System.out.println(s.substring(1, s.length() - 1));
        }
    }

    private static class InputReader {
        private BufferedReader r;
        private StringTokenizer st;

        public InputReader(InputStream stream) {
            r = new BufferedReader(new InputStreamReader(stream), 16384);
            st = null;
        }

        public String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(r.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return st.nextToken();
        }

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

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

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