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;
import java.lang.Math; 
import java.lang.*;

public class Main
 {
  public static void main(String[] args) 
  {
    Scanner input = new Scanner(System.in);
    int a = input.nextInt();
    if ( a % 2 == 0)
    {
      a = a/2;
      a = (int)Math.pow(2,a);
      System.out.println(a);
    }
    else
    {
      System.out.println(0);
    }
  }
}