python3递归思路

def func(n):
    h = n//3
    n = (n//3)+(n%3)
    if n < 2:
        h +=0
    elif n == 2:
        h +=1
    else:
        h += func(n)
    return h
while True:
    try:
        n = int(input())
        if n == 0:
            break
        else:
            print(func(n))
    except:
        break