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;
// taken from https://github.com/DionysiosB/CodeForces
public class A1182 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int n = input.nextInt();
        // Every two blocks make 2x3
        // Replicating on left side, upside, downside,rightside
        // Makes 3xN shapes via different ways
        // Hence for each increase with power of 2
        long ans = n % 2 == 1 ? 0 : (1 << (n/2));
        System.out.println(ans);
        input.close();
    }
}
