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.
from sys import stdin,stdout
Pi = lambda x: stdout.write(str(x) + '\n')
Ps = lambda x: stdout.write(str(x))
S = lambda x: x*(x+1) // 2
I = lambda x: 1+(2*x)
R = lambda:stdin.readline()
Ri = lambda x:map(int,x.split())
Rs = lambda x:map(str,x.split())
Rf = lambda x:map(float,x.split())
 
def main():	
	for x in stdin:
		n = int(x)//2
		if int(x)%2:
			Pi(0)
		else:
			Pi(1<<n)


if __name__=='__main__':
	main()

# 60 == 360
