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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Collections;
import java.util.Scanner;

public class Main {

    public static void convertStringArray (String[] strArr, int[] intArr) {
        for (int i = 0; i < strArr.length; i++) {
            intArr[i] = Integer.parseInt(strArr[i]);
        }
    }

    public static void convertStringArray (String[] strArr, Long[] longArr) {
        for (int i = 0; i < strArr.length; i++) {
            longArr[i] = Long.parseLong(strArr[i]);
        }
    }

    public static void main(String[] args) throws IOException {

        Scanner input = new Scanner(System.in);
        int n = input.nextInt();

        if (n % 2 != 0) {
            System.out.println(0);
        } else {
            System.out.println(2 << ((n >> 1) - 1));
        }


    }
}