太秀了

笨办法，每次循环求剩的瓶子
巧办法，除以2

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 (n == 0) {
                break;
            } else if (n < 3) {
                System.out.println(n);
            } else {
                int c = 0;
                c += n / 3;
                n = n / 3 + n %3;
                while (n > 2) {
                    c += n / 3;
                    n = n / 3 + n % 3;
                }
                if (n == 2) {
                    c++;
                }
                System.out.println(c);
            }
        }
    }
}