def f(curr, end, step):
    if curr > end:
        return 0
    if curr == end and step == 7:
        return 1
    if curr == end and step != 7:
        return 0
    if curr < end:
        return f(curr + 1, end, step + 1) + f(curr + 4, end, step + 1) + f(curr * 2, end, step + 1)
print(f(3, 27, 0))