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.
######################################################################
# Write your code here
import sys
input = sys.stdin.readline
#import resource
#resource.setrlimit(resource.RLIMIT_STACK, [0x10000000, resource.RLIM_INFINITY])
#sys.setrecursionlimit(0x100000)
# Write your code here
RI = lambda : [int(x) for x in sys.stdin.readline().strip().split()]
rw = lambda : input().strip().split()
from collections import defaultdict as df
#import heapq 
#heapq.heapify(li) heappush(li,4) heappop(li)
#import random
#random.shuffle(list)
#infinite = float('inf')
#######################################################################)

def solve(n):
    if(n%2==1):
        print(0)
    else:
        n=n//2
        print(pow(2,n))


n=int(input())

solve(n)
