You have a given integer n. Find the number of ways to fill all 3 × n tiles with the shape described in the picture below. Upon filling, no empty spaces are allowed. Shapes cannot overlap.

<image> This picture describes when n = 4. The left one is the shape and the right one is 3 × n tiles. 

Input

The only line contains one integer n (1 ≤ n ≤ 60) — the length.

Output

Print the number of ways to fill.

Examples

Input


4


Output


4

Input


1


Output


0

Note

In the first example, there are 4 possible cases of filling.

In the second example, you cannot fill the shapes in 3 × 1 tiles.

import java.io.*;
import java.util.HashMap;
import java.util.StringTokenizer;



public class Main {

    static int a[];
    static int l[];
    static int ans[];
    static HashMap<Integer, Boolean> map = new HashMap<>();

    public static void main (String [] args) throws Exception {
        InputReader reader = new InputReader();
        PrintWriter out = new PrintWriter(System.out);

        int n, m;
        n = reader.nextInt();

        if( 3*n % 6 == 0 )
        {
            System.out.println( (int)(Math.pow(2, n/2)));
        }else{
            System.out.println(0);
        }

        out.flush();
    }


    static class InputReader {
        BufferedReader reader;
        StringTokenizer tokenizer;

        InputReader() {
            reader = new BufferedReader(new InputStreamReader(System.in));
            tokenizer = null;
        }

        String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return tokenizer.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }
        double nextDouble() {
            return Double.parseDouble(next());
        }

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