Educational Codeforces Round 69 [Rated for Div. 2]
Difference between en3 and en4, changed 2,840 character(s)
Hello Codeforces!↵

On [contest_time:1197] [contest:1197] 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 problems** and **2 hours** to solve them.↵
 ↵
The problems were invented and prepared by Roman [user:Roms,2019-07-13] Glazov, Adilbek [user:adedalic,2019-07-13] Dalabaev, Vladimir [user:Vovuh,2019-07-13] Petrov, Ivan [user:BledDest,2019-07-13] Androsov, Maksim [user:Ne0n25,2019-07-13] Mescheryakov and me. Also huge thanks to Mike [user:MikeMirzayanov,2019-07-13] Mirzayanov for great systems Polygon and Codeforces.↵

Good luck to all participants!↵

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

_Hello Codeforces!_↵

_We hope your summer is going well!_ ↵

_Last Friday we finished the second edition of the Tech Scouts Summer Camp, with **70 participants**, **20 different nationalities** and many solved problems._ ↵
_We had **6 participants with a full scholarship** thanks to the collaboration between **Harbour.Space and Codeforces** and we are working on increasing this number next year._ ↵

_We would also like to remind you that we offer scholarships for our technical programmes, such as **Computer Science, Data Science and Cyber Security**._ ↵

_They are set in such a way that doesn’t require additional applications — we believe in merit and potential, and so what you put in your application to the university will be our criteria._↵

_You could be just the diamond we’re looking for, but you’ll never know unless you apply!_↵

<center style="margin:2.5em;">↵
<a href="https://harbour.space/admissions/scholarship?utm_source=codeforces&utm_medium=partners" style="text-decoration:none; font-size:18px; background-color:#523996; color:white; font-weight:bold; padding:0.5em 1em;">APPLY HERE&rarr;</a>↵
</center>↵

![ ](/predownloaded/2e/8c/2e8c1a3e1f45c0c4d60b8c358cb3f779e7564686.png)↵

**UPD2:** There will be **6** problems in the contest.


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:Um_nik, 2019-07-22]</td>↵
<td>6</td>↵
<td>111</td>↵
</tr>↵
<tr>↵
<td>2</td>↵
<td>[user:Golovanov399, 2019-07-22]</td>↵
<td>6</td>↵
<td>174</td>↵
</tr>↵
<tr>↵
<td>3</td>↵
<td>[user:PinkRabbit, 2019-07-22]</td>↵
<td>6</td>↵
<td>190</td>↵
</tr>↵
<tr>↵
<td>4</td>↵
<td>[user:dreamoon_love_AA, 2019-07-22]</td>↵
<td>6</td>↵
<td>198</td>↵
</tr>↵
<tr>↵
<td>5</td>↵
<td>[user:_twilight, 2019-07-22]</td>↵
<td>6</td>↵
<td>232</td>↵
</tr>↵
<tr>↵
<td>6</td>↵
<td>[user:HIR180, 2019-07-22]</td>↵
<td>6</td>↵
<td>252</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:greencis, 2019-07-22]</td>↵
<td><b><font color="green">122</font></b><b>:<font color="red">-29</font></b></td></td>↵
</tr>↵
<tr>↵
<td>2</td>↵
<td>[user:Ali_Zaiback, 2019-07-22]</td>↵
<td><b><font color="green">26</font></b></td></td>↵
</tr>↵
<tr>↵
<td>3</td>↵
<td>[user:racsosabe, 2019-07-22]</td>↵
<td><b><font color="green">22</font></b><b>:<font color="red">-7</font></b></td></td>↵
</tr>↵
<tr>↵
<td>4</td>↵
<td>[user:plusplus6408, 2019-07-22]</td>↵
<td><b><font color="green">14</font></b></td></td>↵
</tr>↵
<tr>↵
<td>5</td>↵
<td>[user:Flamire, 2019-07-22]</td>↵
<td><b><font color="green">14</font></b><b>:<font color="red">-3</font></b></td></td>↵
</tr>↵
<tr>↵
<td>6</td>↵
<td>[user:crvineeth97, 2019-07-22]</td>↵
<td><b><font color="green">13</font></b><b>:<font color="red">-2</font></b></td></td>↵
</tr>↵
</tbody>↵
</table>↵
397 successful hacks and 420 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:dorijanlendvaj, 2019-07-22]</td>↵
<td>0:01</td>↵
</tr>↵
<tr>↵
<td>B</td>↵
<td>[user:Um_nik, 2019-07-22]</td>↵
<td>0:04</td>↵
</tr>↵
<tr>↵
<td>C</td>↵
<td>[user:beefman, 2019-07-22]</td>↵
<td>0:06</td>↵
</tr>↵
<tr>↵
<td>D</td>↵
<td>[user:Um_nik, 2019-07-22]</td>↵
<td>0:12</td>↵
</tr>↵
<tr>↵
<td>E</td>↵
<td>[user:Benq, 2019-07-22]</td>↵
<td>0:11</td>↵
</tr>↵
<tr>↵
<td>F</td>↵
<td>[user:Um_nik, 2019-07-22]</td>↵
<td>0:31</td>↵
</tr>↵
</tbody>↵
</table>↵

**UPD3:** [Editorial is out](https://codeforces.com/blog/entry/68615)

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en4 English PikMike 2019-07-23 17:53:10 2840
ru6 Russian PikMike 2019-07-23 17:52:34 2798
ru5 Russian PikMike 2019-07-22 16:59:24 11 Мелкая правка: 'UPD2:** В контесте будет **6** задач' -> 'UPD2:** В раунде будет **6** задач.'
en3 English PikMike 2019-07-22 16:58:52 58
ru4 Russian PikMike 2019-07-22 16:58:11 44
ru3 Russian Una_Shem 2019-07-21 22:14:23 12 Мелкая правка: ' вас:\n\n_Hello Codeforce' -> ' вас:\n\n_Привет, Codeforce'
ru2 Russian Una_Shem 2019-07-21 20:36:45 1308
en2 English Una_Shem 2019-07-21 19:52:16 1284
en1 English PikMike 2019-07-21 14:45:01 1276 Initial revision for English translation
ru1 Russian PikMike 2019-07-21 14:44:36 1397 Первая редакция (опубликовано)