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 math
mod=1000000007
def power(a,b):
    res=1
    b=b%(mod-1)
    while(b>0):
        if b%2!=0:
            res=((res%mod)*(a%mod))%mod
        b=b//2
        a=a%mod
        a=(a*a)%mod
    res=res%mod
    return res
#n=int(input())
#a=[int(i) for i in input().split()]
#c=[[0 for x in range(1001)] for y in range(1001)]
#n,q=[int(i) for i in input().split()]
#a.sort(reverse=True)
n=int(input())
if n%2==0:
    x=n//2
    x=2**x
    print(x)
else:
    print("0")