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.PrintWriter;
import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);
        final PrintWriter pw = new PrintWriter(System.out);

        int n = sc.nextInt();
        int n3 = n * 3;

        if (n3 % 6 == 0) {
            pw.println((int)Math.pow(2, n3 / 6.));
        } else {
            pw.println(0);
        }

        pw.flush();
    }
}
