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 prac {
  static Scanner sc = new Scanner(System.in);
  public static void main(String args[]) {
    // int t=sc.nextInt();
    // while(t-->0)
    // {
      int n=sc.nextInt();
      if(n%2!=0)
      System.out.println("0");
      else
      {
        n/=2;
        System.out.println(1<<n);
      }
          // }
  }
}
