import java.util.Scanner;

/**
 * @author leekari
 * @date 2020/10/14 14:26
 * @description
 */

/**
 * n个空瓶可以喝多少瓶酒问题，3空瓶 => 1酒
 */
public class Bottom {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int nextInt = Integer.parseInt(scanner.nextLine());
        while(nextInt != 0){
            System.out.println(nextInt / 2);
            if (scanner.hasNextLine()){
                nextInt = Integer.parseInt(scanner.nextLine());
            }
        }
    }
}