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.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

/**
 * @author Andrei Chugunov
 */
public class A {

    private BufferedReader br;
    private PrintWriter out;
    private StringTokenizer st;
    void solve() throws IOException {
        String result = "-1";

        int x = nextInt();
        int a;
        int b;
        for (int i = 1; i <= x; i++) {
            a = i;
            for (int j = 1; j <= x; j++) {
                b = j;
                if (a % b == 0) {
                    if (a / b < x) {
                        if (a * b > x) {
                            result = a + " " + b;
                            break;
                        }
                    }
                }
            }
        }
        out.println(result);
    }

    A() throws IOException {
        br = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);
        solve();
        out.close();
    }

    public static void main(String[] args) throws IOException {
        new A();
    }

    String nextToken() {
        while (st == null || !st.hasMoreTokens()) {
            try {
                st = new StringTokenizer(br.readLine());
            } catch (Exception e) {
                return null;
            }
        }
        return st.nextToken();
    }

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

    String nextString() throws IOException {
        return br.readLine();
    }

    long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }
}