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 collections import defaultdict as dc
from heapq import *
import math
import bisect
import sys
from collections import deque as dq
from heapq import heapify,heappush,heappop
mod=10**12
def inp():
    p=int(input())
    return p
def line():
    p=list(map(int,input().split()))
    return p
def digit(n):
    s=str(n)
    p=0
    for i in s:
        p+=(int(i))**2
    return p
n=inp()
if n&1:
	print(0)
else:
	print(pow(2,n//2))	
	
	
	
		
