1. 
/*
 * ACM Contest training
 * Problem: 11877 - The Coco-Cola Store
 * Link: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=226&page=show_problem&problem=2999
 *
 * @author Christoph Goettschkes
 * @version 1.0, 11/08/2010
 *
 * Method : Ad-Hoc
 * Status : Accepted
 * Runtime: 0.108
 */

import java.io.*;

class Main
{
	public static void main(String[] args) throws IOException {
		BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

		int n = Integer.parseInt(reader.readLine().trim());

		while (n > 0) {
			int d = 0;

			int full = 0;
			int empty = n;
			int counter = 7;
			while (empty > 0 && counter > 0) {
				full = empty / 3;
				empty %= 3;
				d += full;
				empty += full;
				full = 0;
				counter--;
				if (empty == 2)
					empty++;
			}
			System.out.println(d);
			
			n = Integer.parseInt(reader.readLine().trim());
		}
	}
}