import math

def nosfw(b, n):
    ans = math.floor((b+1)*b**(n-1))
    if n >= 4:
        for x in range(math.floor(n/2)-1):
            if n == 4:
                ans = ans - nosfw(b, math.floor(n/2)-x)
            elif n > 4 and n < 7:
                ans = ans - (3)*nosfw(b, math.floor(n/2)-x)
    return ans


print(nosfw(2,7))