in

8 1 2
2 2 4
1 3
3 1

out

4

解释：

Time	Thing
0	Drinking
1	Drinking
2	Learning
3	Learning
4	Skiing on 2
5	Skiing on 2
6	Skiing on 2
7	Skiing on 2
8	Leaving

https://guodonglovesoi.blog.luogu.org/post-2948-ti-xie 5

https://www.luogu.com.cn/blog/zkdxlpro/solution-p2948 5

https://www.luogu.com.cn/blog/CreeperLKF/solution-p2948 2

上个帖子算错了，丢人。