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.util.Scanner;
public class FillingShapes
{
    public static void main(String[] args)
    {
        Scanner s = new Scanner(System.in);
        int loop = s.nextInt(), counter=0, pwoer=0;
        for(int i=1; i<=loop; i++)
            if(i%2==0)
            {
                counter++;
                pwoer=counter;
            }       
        counter=1;
        if(loop%2!=0) System.out.println("0");
        else
        {
            for(int i=1; i<=pwoer; i++)
                counter *= 2;
            System.out.println(counter);
        }
    } 
}
