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.


/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
import java.io.BufferedInputStream;
import java.util.ArrayList;
import java.util.Arrays;

import java.util.Scanner;

/**
 *
 * @author Elizabeth
 */
public class Main {

     public static void main(String[] args) {
        Scanner leer=new Scanner(System.in);
        int n=leer.nextInt();
        if(n%2==0){
            System.out.printf("%d",1<<n/2);
        }else{
            System.out.println(0);
        }
        
    }
  
   

}
