汽水瓶

汽水瓶

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextInt()) {
            int n = in.nextInt();
            if (n == 0) break;
            //每次能兑换多少瓶饮料
            int count = 0;
            int sum = 0;
            while( n > 0) {
                if (n < 3) break;
                count = n / 3;
                //兑换完后更新空瓶子数
                n = n % 3 + count;
                //如果空瓶子数<3，达不到兑换标准，则向老板借一个
                if(n < 3) n = n + 1;
                sum += count;
            }
            System.out.println(sum);
        }
    }
}