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 final class A1182 {
	
	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder str = new StringBuilder();
			
			
			int n = Integer.parseInt(br.readLine());
			
			 if(n%2 == 1 || n == 0) {
			    str.append("0");
			}
			else {
			    str.append((long)Math.pow(2,n/2));
			}
		System.out.print(str);
		
	}
	
}
