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.*;

public class FillShape{

   public static void main(String[] args){
      Scanner input = new Scanner(System.in);
      int n = input.nextInt();
      System.out.println(poss(n));
   }

   public static int poss(int n){
      if(n%2!=0){
         return 0;
      }else{
         int poss = 1;
         for(int i=0; i<n/2; i++){
            poss *= 2;
         }
         return poss;
      }
   }

}