题解 | #汽水瓶#

//JAVA 递归
import java.util.*;
public class Main {
        public static void main(String[] args){
            Scanner sc = new Scanner(System.in);
            while(sc.hasNext()){
                int n = sc.nextInt();
                if(0 == n){
                    return;
                }
             System.out.println(getClass(n));
            }
        }
        public static int getClass(int n){
            if(n == 1){
                return 0;
            }else if(n == 2){
                return 1;
            }else{
                int a = n%3;
                int count = n/3;
                 n =  a + count;
                return count += getClass(n);
            }
        }

}