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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class ABC {

    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

    public static void main(String[] args) throws IOException {
        int n = Integer.parseInt(br.readLine());
        if(n%2!=0) {
            System.out.println(0);
        }
        else {
            System.out.println((int)Math.pow(2,n/2));
        }
    }

    /*public static void main2(String[] args) {
        String[] in = br.readLine().split()
    }*/

}
