Hello codeforces! Goodbye Renyin!

In a flash, 2022 is over. The Rabbit year is coming, now the world is full of PinkRabbit. But the group of PinkRabbits was infiltrated by a RinkRabbit.

The king of PinkRabbit has noticed. He decided to hold a "Rabbing test" to identify the RinkRabbit. You, the Volt, an assistant of the king, need to help the king to complete the test.

The picture shows a RinkRabbit walking toward.

We will hold Goodbye Renyin, which will take place on Friday, January 20, 2023 at 13:00^UTC+8

The duration time is 5 hours, and there will be 5 problems.

The rule uses pretests, and only the last submit will be counted in.

There are simple and interesting problems, welcome to play!

Writers: changruinian2020 ix35 MagicalFlower Melania Qingyu

Some Explanation:

The Renyin is the 39th stem and branch (An ancient Chinese chronology) and after the day named Chuxi is the Chinese new year, the contest will be held the day before Chuxi.

And unfortunately, our languages support only simplified Chinese, we are very sorry for this, but you can change language of the whole website under the webpage and then sign up a account.