import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); while(true) { int n = in.nextInt(); if (n == 0) break; if (n == 1) { System.out.println(0); continue; } int res = 0; // n == 2 特殊情况 while (n / 3 > 0 || n == 2) { // 兑换的瓶数 re...