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.*;
import java.io.*;
public class shape
{
    public static void main(String args[]) throws Exception
    {
      BufferedReader b=new BufferedReader(new InputStreamReader(System.in));
      BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
    int n=Integer.parseInt(b.readLine());
    int m=0;
    if(n%2==0)
    {
        m=n/2;
        m=(int)Math.pow(2,m);
    }
    else
        m=0;
        bw.write(Integer.toString(m));
  bw.flush();
  bw.close();
  b.close();
 
    }
}