Educational Codeforces Round 108 [Rated for Div. 2]
Difference between en2 and en3, changed 2,622 character(s)
Hello Codeforces!↵

On [contest_time:1519] [contest:1519] 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.com/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,2021-04-28] Glazov, Adilbek [user:adedalic,2021-04-28] Dalabaev, Vladimir [user:vovuh,2021-04-28] Petrov, Ivan [user:BledDest,2021-04-28] Androsov, Maksim [user:Neon,2021-04-28] Mescheryakov and me. Also huge thanks to Mike [user:MikeMirzayanov,2021-04-28] Mirzayanov for great systems Polygon and Codeforces.↵

Good luck to all the participants!↵

Our friends at Harbour.Space also have a message for you:↵

<img alt="Codeforces and Harbour.Space" src="https://codeforces.com/predownloaded/70/30/7030707cf9642a540a22fca9fb4665bb35f593f8.png" style="float:center;height: 250px; margin: 10px; max-width:50%;"/>↵

_Hey, Codeforces!_ ↵

_Once again, it is time for another exciting **scholarship opportunity** from Harbour.Space!_ ↵

_This time we have partnered with PhazeRo to open the door for an exciting career in technology for the most talented people in our network._ ↵

_In partnership with PhazeRo, we are offering a **full scholarship** to study for a Master’s in Data Science at Harbour.Space while working as a [Junior Data Scientist at PhazeRo](https://harbour.space/scholarships/data-science-apprenticeship-phazero?utm_source=codeforces&utm_medium=referral&utm_campaign=phazero-data-science)!_↵

_**Scholarship Requirements:**_↵

- _Bachelor's Degree_↵
- _Professional fluency in English_↵
- _Proficiency with data mining, mathematics, and statistical analysis._↵
- _Experience with Tableau, SQL, and programming languages (i.e., Python, R, Java)_↵

_**Scholarship Highlights:**_↵

1. _Study in Europe’s most exciting tech cities_↵
1. _Full tuition fee covered (€22,900)_ ↵
1. _Competitive compensation for the internship at PhazeRo (€700 / month)_ ↵
1. _Opportunity to join PhazeRo full-time after graduation_ ↵



<img alt="Codeforces and Harbour.Space" src="https://codeforces.com/predownloaded/60/71/60714ce39dd7584b17a768ef803dfcc5ac3e75c2.png" style="float:center;height: 300px; margin: 10px; max-width:50%;"/>↵


_**Some of the advantages of working at PhazeRo:**_↵

- _Possibility of a job upon graduation_↵
- _Immerse into an International Company_↵
- _Diversity Program_↵
- _Professional Development_↵
- _Be part of a company that is building the region's largest engineering team_↵


_We have previously partnered with other companies like OneRagtime, Hansgrohe, Coherra, and Remy Robotics to empower young talents around the world and help them boost their tech career._↵

_We are always happy to see Codeforces members join the Harbour.Space family. [Apply now](https://harbour.space/scholarships/data-science-apprenticeship-phazero?utm_source=codeforces&utm_medium=referral&utm_campaign=phazero-data-science) to get a chance to learn from the best in the field and kickstart your career!_↵

_Keep in touch and follow us on [LinkedIn](https://www.linkedin.com/school/harbour-space/) for more scholarship opportunities. And follow us on [Instagram](https://www.instagram.com/harbour.space/) to evidence student life, events, and success stories from our apprenticeship program students._↵

_Good luck on your round, and see you next time!_ ↵

_Harbour.Space University_↵

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, 2021-04-29]</td>↵
<td>6</td>↵
<td>186</td>↵
</tr>↵
<tr>↵
<td>2</td>↵
<td>[user:vepifanov, 2021-04-29]</td>↵
<td>6</td>↵
<td>188</td>↵
</tr>↵
<tr>↵
<td>3</td>↵
<td>[user:Um_nik, 2021-04-29]</td>↵
<td>6</td>↵
<td>251</td>↵
</tr>↵
<tr>↵
<td>4</td>↵
<td>[user:Farhod_Farmon, 2021-04-29]</td>↵
<td>5</td>↵
<td>65</td>↵
</tr>↵
<tr>↵
<td>5</td>↵
<td>[user:noimi, 2021-04-29]</td>↵
<td>5</td>↵
<td>76</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:zhoumofei, 2021-04-29]</td>↵
<td><b><font color="green">50</font></b><b>:<font color="red">-50</font></b></td></td>↵
</tr>↵
<tr>↵
<td>2</td>↵
<td>[user:mufeng.wei, 2021-04-29]</td>↵
<td><b><font color="green">24</font></b><b>:<font color="red">-4</font></b></td></td>↵
</tr>↵
<tr>↵
<td>3</td>↵
<td>[user:SSerxhs, 2021-04-29]</td>↵
<td><b><font color="green">22</font></b><b>:<font color="red">-9</font></b></td></td>↵
</tr>↵
<tr>↵
<td>4</td>↵
<td>[user:mahesh_dubey, 2021-04-29]</td>↵
<td><b><font color="green">13</font></b><b>:<font color="red">-1</font></b></td></td>↵
</tr>↵
<tr>↵
<td>5</td>↵
<td>[user:haminh0307, 2021-04-29]</td>↵
<td><b><font color="green">11</font></b><b>:<font color="red">-5</font></b></td></td>↵
</tr>↵
</tbody>↵
</table>↵
463 successful hacks and 1684 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:Geothermal, 2021-04-29]</td>↵
<td>0:01</td>↵
</tr>↵
<tr>↵
<td>B</td>↵
<td>[user:turmax, 2021-04-29]</td>↵
<td>0:02</td>↵
</tr>↵
<tr>↵
<td>C</td>↵
<td>[user:eecs, 2021-04-29]</td>↵
<td>0:04</td>↵
</tr>↵
<tr>↵
<td>D</td>↵
<td>[user:abc864197532, 2021-04-29]</td>↵
<td>0:04</td>↵
</tr>↵
<tr>↵
<td>E</td>↵
<td>[user:noimi, 2021-04-29]</td>↵
<td>0:28</td>↵
</tr>↵
<tr>↵
<td>F</td>↵
<td>[user:rainboy, 2021-04-29]</td>↵
<td>1:16</td>↵
</tr>↵
</tbody>↵
</table>↵

**UPD:** [Editorial is out](https://codeforces.com/blog/entry/90212)

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en3 English awoo 2021-04-30 18:39:25 2622
ru4 Russian awoo 2021-04-30 18:38:54 2602
ru3 Russian Una_Shem 2021-04-28 22:42:37 2936
ru2 Russian Una_Shem 2021-04-28 18:25:54 0 (опубликовано)
en2 English Una_Shem 2021-04-28 18:25:44 2771 (published)
en1 English awoo 2021-04-28 14:52:47 1284 Initial revision for English translation (saved to drafts)
ru1 Russian awoo 2021-04-28 14:51:57 1400 Первая редакция (сохранено в черновиках)