就是三个瓶盖换一个,瓶盖数++,不知道哪年的题目,水题
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
public class Main {
static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
static PrintWriter pw = new PrintWriter(System.out);
static int n, res;
public static void main(String[] args) throws Exception {
n = Integer.parseInt(br.readLine());
int temp = n;
while (n >= 3) {
n -= 3;
res += 1;
n++;
}
pw.println(res + temp);
pw.flush();
pw.close();
br.close();
}
}