1072: 汽水瓶

解题思路:

注意事项:

参考代码:

while True:
    try:
        n = int(input())
        if n == 0:
            break
        if n ==1:
            print(0)
        else:
            s = 0
            while n >= 3:
                s += n//3
                n = n//3+n%3
            if n == 2:
                print(s+1)
            else:
                print(s)
    except:
        break