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.StringTokenizer;
 
 
public class test {
 
	static int[] firstpos=new int[26];
	
	public static void main(String[] args) throws NumberFormatException, IOException{
	    BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
	    int n=Integer.parseInt(br.readLine());
	    if(n%2!=0) {
	    	System.out.println(0);
	    }
	    else {
	    	System.out.println((int)Math.pow(2, n/2));
	    }
	}
	
	
 
}
