题解 | #汽水瓶#

import java.util.*;
import java.io.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str = null;
        while((str = br.readLine())!= null){
            int a = Integer.parseInt(str);
            if (a < 2) continue;
            System.out.println(a / 2);
        }
    }
}