python 解法

python 解法

def drink_count(n):
    if n < 2:
        return 0
    if n ==2:
        return 1
    else:
        return n//3 + drink_count(n//3+n%3)

if '__name__' == '__main__':
    while True:
        try:
            n = int(input())
            if n == 0:
                break
            else:
                print(drink_count(n))
        except:
            break