We will hold <a href="https://atcoder.jp/contests/arc155">AtCoder Regular Contest 155</a>. - Contest URL: https://atcoder.jp/contests/arc155 - Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20230129T2100&p1=248 - Duration: 120 minutes - Number of Tasks: 6 - Writer: <a href="/users/chinerist" class="username"><span class="user-orange">chinerist</span></a> - Tester: <img src="//img.atcoder.jp/assets/icon/crown_silver.png"> <a href="/users/tatyam" class="username"><span style="color:#FF6040;">tatyam</span></a>, <a href="/users/satashun" class="username"><span class="user-red">satashun</span></a> - Rated range: ~ 2799 The point values will be 400-500-700-800-900-1000. We are looking forward to your participation!

We will hold <a href="https://atcoder.jp/contests/abc287">UNIQUE VISION Programming Contest 2023 New Year (AtCoder Beginner Contest 287)</a>. - Contest URL: https://atcoder.jp/contests/abc287 - Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20230128T2100&p1=248 - Duration: 100 minutes - Number of Tasks: 8 - Writer: <a href="/users/KoD" class="username"><span class="user-red">KoD</span></a>, <a href="/users/m_99" class="username"><span class="user-orange">m_99</span></a>, <a href="/users/PCTprobability" class="username"><span class="user-orange">PCTprobability</span></a>, <a href="/users/kyopro_friends" class="username"><span class="user-orange">kyopro_friends</span></a>, <a href="/users/nok0" class="username"><span class="user-orange">nok0</span></a> - Tester: <a href="/users/yuto1115" class="username"><span class="user-red">yuto1115</span></a>, <a href="/users/physics0523" class="username"><span class="user-orange">physics0523</span></a> - Rated range: ~ 1999 The point values will be 100-200-300-400-500-500-600-600. We are looking forward to your participation!

We will hold <a href="https://atcoder.jp/contests/ahc017">THIRD PROGRAMMING CONTEST 2022（AtCoder Heuristic Contest 017）</a>. - Contest URL: https://atcoder.jp/contests/ahc017 - Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20230128T1200&p1=248 - Duration: 8 days - Writer: <a href="/users/wata_admin" class="username"><span class="user-unrated">wata_admin</span></a> - Rated range: All (Heuristic Rating) The goal of AHC is to create a better solution to a problem for which it is difficult to find the optimal solution. We are looking forward to your participation!

We will hold <a href="https://atcoder.jp/contests/arc154">AtCoder Regular Contest 154</a>. - Contest URL: https://atcoder.jp/contests/arc154 - Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20230122T2100&p1=248 - Duration: 120 minutes - Number of Tasks: 6 - Writer: <a href="/users/PCTprobability" class="username"><span class="user-orange">PCTprobability</span></a> - Tester: <img src="//img.atcoder.jp/assets/icon/crown_silver.png"> <a href="/users/tatyam" class="username"><span style="color:#FF6040;">tatyam</span></a>, <img src="//img.atcoder.jp/assets/icon/crown_bronze.png"> <a href="/users/maspy" class="username"><span class="user-red">maspy</span></a> - Rated range: ~ 2799 The point values will be 300-400-500-700-900-900. We are looking forward to your participation!

We will hold <a href="https://atcoder.jp/contests/abc286">UL Systems Programming Contest 2023(AtCoder Beginner Contest 286)</a>. - Contest URL: https://atcoder.jp/contests/abc286 - Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20230121T2100&p1=248 - Duration: 100 minutes - Number of Tasks: 8 - Writer: <a href="/users/mechanicalpenciI" class="username"><span class="user-orange">mechanicalpenciI</span></a>, <a href="/users/nok0" class="username"><span class="user-orange">nok0</span></a>, <a href="/users/physics0523" class="username"><span class="user-orange">physics0523</span></a>, <a href="/users/kyopro_friends" class="username"><span class="user-orange">kyopro_friends</span></a>, <a href="/users/PCTprobability" class="username"><span class="user-orange">PCTprobability</span></a>, <img src="//img.atcoder.jp/assets/icon/crown_bronze.png"> <a href="/users/chokudai" class="username"><span class="user-red">chokudai</span></a>, <a href="/users/yuto1115" class="username"><span class="user-red">yuto1115</span></a>, <a href="/users/m_99" class="username"><span class="user-orange">m_99</span></a> - Tester: <a href="/users/MMNMM" class="username"><span class="user-yellow">MMNMM</span></a>, <a href="/users/Nyaan" class="username"><span class="user-orange">Nyaan</span></a> - Rated range: ~ 1999 The point values will be 100-200-300-400-500-500-600-600. We are looking forward to your participation!

We will hold <a href="https://atcoder.jp/contests/arc153">AtCoder Regular Contest 153</a>. - Contest URL: https://atcoder.jp/contests/arc153 - Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20230114T2100&p1=248 - Duration: 120 minutes - Number of Tasks: 6 - Writer: <img src="//img.atcoder.jp/assets/icon/crown_bronze.png"> <a href="/users/maspy" class="username"><span class="user-red">maspy</span></a> - Tester: <img src="//img.atcoder.jp/assets/icon/crown_bronze.png"> <a href="/users/potato167" class="username"><span class="user-red">potato167</span></a>, <a href="/users/satashun" class="username"><span class="user-red">satashun</span></a> - Rated range: ~ 2799 The point values will be 300-500-600-800-800-1000. We are looking forward to your participation!

We will hold <a href="https://atcoder.jp/contests/abc285">AtCoder Beginner Contest 285</a>. - Contest URL: https://atcoder.jp/contests/abc285 - Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20230115T2100&p1=248 - Duration: 100 minutes - Number of Tasks: 8 - Writer: <a href="/users/physics0523" class="username"><span class="user-orange">physics0523</span></a>, <a href="/users/kyopro_friends" class="username"><span class="user-orange">kyopro_friends</span></a>, <a href="/users/yuto1115" class="username"><span class="user-red">yuto1115</span></a>, <a href="/users/m_99" class="username"><span class="user-orange">m_99</span></a> - Tester: <a href="/users/leaf1415" class="username"><span class="user-orange">leaf1415</span></a>, <img src="//img.atcoder.jp/assets/icon/crown_bronze.png"> <a href="/users/cn449" class="username"><span class="user-red">cn449</span></a> - Rated range: ~ 1999 The point values will be 100-200-300-400-500-500-600-600. We are looking forward to your participation!

We will hold <a href="https://atcoder.jp/contests/abc284">AtCoder Beginner Contest 284</a>. - Contest URL: https://atcoder.jp/contests/abc284 - Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20230107T2100&p1=248 - Duration: 100 minutes - Number of Tasks: 8 - Writer: <a href="/users/Nyaan" class="username"><span class="user-orange">Nyaan</span></a>, <a href="/users/yuto1115" class="username"><span class="user-red">yuto1115</span></a> - Tester: <a href="/users/KoD" class="username"><span class="user-red">KoD</span></a>, <a href="/users/m_99" class="username"><span class="user-orange">m_99</span></a> - Rated range: ~ 1999 The point values will be 100-200-300-400-500-500-600-600. We are looking forward to your participation!

We've published the results of the GP30 race of the current and previous seasons. - [Season 2019](https://img.atcoder.jp/file/GP30.html) - [Season 2020](https://img.atcoder.jp/file/gp30/race2020.html) ([CSV Format](https://img.atcoder.jp/file/gp30/race2020.csv)) - [Season 2021](https://img.atcoder.jp/file/gp30/race2021.html) ([CSV Format](https://img.atcoder.jp/file/gp30/race2021.csv)) - [Season 2022](https://img.atcoder.jp/file/gp30/race2022.html) ([CSV Format](https://img.atcoder.jp/file/gp30/race2022.csv)) We are planning to host an onsite WTF in 2023 with the top 8 contestants of each season. We'll announce more details of the Finals once we decide. Above all, congrats to the all Finalists!

Thank you for participating in AtCoder. We apologize for the inconvenience caused by the problem. We apologize for any inconvenience this may have caused to those who participated on Christmas Day. This is entirely the responsibility of AtCoder, as all questions were created in-house and no sponsor companies were involved in any way. Normally, such incomplete data would result in an Unrated rating, but in this case, the number of people affected is small, so we have decided to give the test case a Rated" because the number of affected users is small. The number of users who will be affected is small, so we have decided to rate them as "Rated" except for the case where a different judge status is given only to the test case that has a flaw. We have decided to rate the test as "Rated" because it would be closer to the correct evaluation of the test. The following 218 contestants were unrated. We apologize for not being able to rate them, even though they took time out of their precious time to participate in the contest. https://img.atcoder.jp/abc283/list2.txt We will judge Rated/Unrated on a case-by-case basis, but we will mainly use the following criteria. Is the contest fair and equitable (will it not favor or disadvantage a particular group of users? The decision will be made based on the following criteria. Although such mistakes inevitably occur due to the structure of the question making process, we would like to minimize them as much as possible. We apologize for any inconvenience this may have caused. We look forward to your continued support of AtCoder. Naohiro Takahashi (chokudai) (This text is translated by DeepL.)