Educational Codeforces Round 99 [Rated for Div. 2]
Difference between en3 and en4, changed 2,630 character(s)
Hello Codeforces!↵

On [contest_time:1455] [contest:1455] will start.↵

Series of Educational Rounds continue being held as [Harbour.Space University](https://harbour.space/) initiative! You can read the details about the cooperation between [Harbour.Space University](https://harbour.space/) and Codeforces in the <a href="http://codeforces.net/blog/entry/51208">blog post</a>.↵
 ↵
This round will be **rated for the participants with rating lower than 2100**. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.↵
 ↵
You will be given **6 or 7 problems** and **2 hours** to solve them.↵
 ↵
The problems were invented and prepared by Roman [user:Roms,2020-11-29] Glazov, Adilbek [user:adedalic,2020-11-29] Dalabaev, Vladimir [user:vovuh,2020-11-29] Petrov, Ivan [user:BledDest,2020-11-29] Androsov, Maksim [user:Ne0n25,2020-11-29] Mescheryakov and me. Also huge thanks to Mike [user:MikeMirzayanov,2020-11-29] Mirzayanov for great systems Polygon and Codeforces.↵

Good luck to all the participants!↵

Congratulations to the winners:↵
<table class='bordertable'>↵
<tbody>↵
<tr>↵
<th>Rank</th>↵
<th>Competitor</th>↵
<th>Problems Solved</th>↵
<th>Penalty</th>↵
</tr>↵
<tr>↵
<td>1</td>↵
<td>[user:neal, 2020-11-30]</td>↵
<td>7</td>↵
<td>223</td>↵
</tr>↵
<tr>↵
<td>2</td>↵
<td>[user:jiangly, 2020-11-30]</td>↵
<td>7</td>↵
<td>224</td>↵
</tr>↵
<tr>↵
<td>3</td>↵
<td>[user:tute7627, 2020-11-30]</td>↵
<td>6</td>↵
<td>190</td>↵
</tr>↵
<tr>↵
<td>4</td>↵
<td>[user:CN_zwang2002, 2020-11-30]</td>↵
<td>6</td>↵
<td>195</td>↵
</tr>↵
<tr>↵
<td>5</td>↵
<td>[user:noimi, 2020-11-30]</td>↵
<td>6</td>↵
<td>213</td>↵
</tr>↵
</tbody>↵
</table>↵


Congratulations to the best hackers:↵
<table class='bordertable'>↵
<tbody>↵
<tr>↵
<th>Rank</th>↵
<th>Competitor</th>↵
<th>Hack Count</th>↵
</tr>↵
<tr>↵
<td>1</td>↵
<td>[user:MarcosK, 2020-11-30]</td>↵
<td><b><font color="green">41</font></b><b>:<font color="red">-6</font></b></td></td>↵
</tr>↵
<tr>↵
<td>2</td>↵
<td>[user:dapingguo8, 2020-11-30]</td>↵
<td><b><font color="green">34</font></b><b>:<font color="red">-2</font></b></td></td>↵
</tr>↵
<tr>↵
<td>3</td>↵
<td>[user:jerdno, 2020-11-30]</td>↵
<td><b><font color="green">12</font></b><b>:<font color="red">-4</font></b></td></td>↵
</tr>↵
<tr>↵
<td>4</td>↵
<td>[user:ARTpositive, 2020-11-30]</td>↵
<td><b><font color="green">10</font></b><b>:<font color="red">-1</font></b></td></td>↵
</tr>↵
<tr>↵
<td>5</td>↵
<td>[user:halyavin, 2020-11-30]</td>↵
<td><b><font color="green">9</font></b><b>:<font color="red">-1</font></b></td></td>↵
</tr>↵
</tbody>↵
</table>↵
357 successful hacks and 769 unsuccessful hacks were made in total!↵

And finally people who were the first to solve each problem:↵
<table class='bordertable'>↵
<tbody>↵
<tr>↵
<th>Problem</th>↵
<th>Competitor</th>↵
<th>Penalty</th>↵
</tr>↵
<tr>↵
<td>A</td>↵
<td>[user:edickLPM, 2020-11-30]</td>↵
<td>0:00</td>↵
</tr>↵
<tr>↵
<td>B</td>↵
<td>[user:SSRS_, 2020-11-30]</td>↵
<td>0:03</td>↵
</tr>↵
<tr>↵
<td>C</td>↵
<td>[user:corol, 2020-11-30]</td>↵
<td>0:03</td>↵
</tr>↵
<tr>↵
<td>D</td>↵
<td>[user:pajenegod, 2020-11-30]</td>↵
<td>0:08</td>↵
</tr>↵
<tr>↵
<td>E</td>↵
<td>[user:neal, 2020-11-30]</td>↵
<td>0:29</td>↵
</tr>↵
<tr>↵
<td>F</td>↵
<td>[user:jiangly, 2020-11-30]</td>↵
<td>0:55</td>↵
</tr>↵
<tr>↵
<td>G</td>↵
<td>[user:jiangly, 2020-11-30]</td>↵
<td>1:17</td>↵
</tr>↵
</tbody>↵
</table>↵


**UPD:** [Editorial is out](https://codeforces.net/blog/entry/85186)

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en4 English awoo 2020-12-01 18:00:34 2630
ru4 Russian awoo 2020-12-01 17:59:46 2604 Мелкая правка: 'шений!\n\n**UPD:' -> 'шений!\n\n\n**UPD:'
en3 English awoo 2020-12-01 17:56:54 72
ru3 Russian awoo 2020-12-01 17:56:35 74
en2 English Una_Shem 2020-11-29 17:14:32 0 (published)
ru2 Russian Una_Shem 2020-11-29 17:14:16 0 (опубликовано)
en1 English awoo 2020-11-29 17:10:34 1285 Initial revision for English translation (saved to drafts)
ru1 Russian awoo 2020-11-29 17:09:52 1401 Первая редакция (сохранено в черновиках)