题解 | #汽水瓶#

while True:
    try:
        input_int = int(input()) # 接收空瓶子的数量
        if input_int !=0:
            drink_num =0
            bottel_num = input_int
            left_bottel_num =0
            while bottel_num >0:

                left_bottel = bottel_num % 3
                bottel_num = bottel_num // 3
                drink_num += bottel_num

                left_bottel_num += left_bottel
    #             print(left_bottel_num)
                if left_bottel_num>=3:
                    drink_num+=1
                    left_bottel_num=left_bottel_num -2

            if left_bottel_num==2:
                drink_num += 1
            print(drink_num)


    except:
        break