сис-мы счисления python

def to(num, base):
    newNum = ''

    while num > 0:
        newNum = str(num % base) + newNum
        num //= base

    return newNum


n = int(input())
var=0
for i in range(9 ** n):
    s9 = to(i, 9)
    if len(s9) == 0:
        continue
    if s9[0] == '0' or len(s9) != n:
        continue
    s3 = to(i, 3)
    if '0' not in s3:
        var+=1
print(var)