Hello, Codeforces!

It’s our pleasure to invite you to Goodbye Renyin, which takes place on Friday, January 20, 2023 at 13:00^UTC+8.

You will have 5 hours to solve 5 problems sorted roughly by difficulty. Each problem is worth 100 points and may have several subtasks. There might be interactive or output-only problems. The contest is open to everyone, though Codeforces-Div. 1-level contestants are more likely to enjoy it. For details, you may check last year’s Goodbye Xinchou (only available in Chinese, Simplified).

The problems are authored by changruinian2020, ix35, MagicalFlower, Melania and Qingyu.

The competition format will be similar to (but a bit different from) China National OI contests: during the contest, each submission will only be run on sample tests (there will be relatively strong samples, though); only your last submission to each problem will be considered valid. The contestants will be ranked first by total score, then by penalty (which is defined as the sum of the submission time of each valid submission). Note that when the contest is running, there is a scoreboard that shows nothing but everyone’s results on sample tests.

The problems will be in Chinese (Simplified). In this contest, we'll put brief English statements in the attachments, but it's still strongly encouraged that you learn Chinese for maximized functionality of our website.

About us: Universal Online Judge (UOJ) is a non-profit competitive programming website maintained by a group of top OI contestants in China. We hold CNOI- and IOI-format contests with at different levels of difficulty. You can find both high-quality ad-hoc problems and applications of the latest Chinese CP techniques on UOJ.

About Renyin: Renyin (壬寅) is the 39-th term in the 60-year Sexagenary cycle (a Chinese system of year numbering), which corresponds to 1902, 1962, 2022, etc. We schedule the contest two days before the Chinese New Year.