Today a horrible thing almost happened: I barely stayed an International Grandmaster on Codeforces after participation in [contest:1870]. I would't say I was exceptionally slow or that I solved problems too clumsily, but for some reason the majority of participants near my level were faster than me on these problems.↵
↵
I recorded a five hour long [video](https://youtu.be/9zd9RGqjSfA) about my adventures. If you're interested in a particular problem, follow the timecodes:↵
↵
<table>↵
<tr>↵
<th>Problem</th>↵
<th>Solving</th>↵
<th>Implementation</th>↵
<th>Editorial</th>↵
</tr>↵
<tr>↵
<td>[problem:1870A]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=97">01:37</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=165">02:45</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=12208">3:23:28</a></td>↵
</tr>↵
<tr>↵
<td>[problem:1870B]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=383">06:23</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=654">10:54</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=12620">3:30:20</a></td>↵
</tr>↵
<tr>↵
<td>[problem:1870C]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=768">12:48</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=852">14:12</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=13260">3:41:00</a></td>↵
</tr>↵
<tr>↵
<td>[problem:1870D]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=1334">22:14</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=1481">24:41</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=14300">3:58:20</a></td>↵
</tr>↵
<tr>↵
<td>[problem:1870E]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=2377">39:37</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=3522">58:42</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=16464">4:34:24</a></td>↵
</tr>↵
<tr>↵
<td>[problem:1870F]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=5463">1:31:03</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=10472">2:54:32</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=9037">2:30:37</a></td>↵
</tr>↵
</table>↵
↵
If you open a video and see it's low quality, you might want to wait several minutes until YouTube processes the higher resolutions.
↵
I recorded a five hour long [video](https://youtu.be/9zd9RGqjSfA) about my adventures. If you're interested in a particular problem, follow the timecodes:↵
↵
<table>↵
<tr>↵
<th>Problem</th>↵
<th>Solving</th>↵
<th>Implementation</th>↵
<th>Editorial</th>↵
</tr>↵
<tr>↵
<td>[problem:1870A]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=97">01:37</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=165">02:45</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=12208">3:23:28</a></td>↵
</tr>↵
<tr>↵
<td>[problem:1870B]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=383">06:23</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=654">10:54</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=12620">3:30:20</a></td>↵
</tr>↵
<tr>↵
<td>[problem:1870C]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=768">12:48</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=852">14:12</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=13260">3:41:00</a></td>↵
</tr>↵
<tr>↵
<td>[problem:1870D]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=1334">22:14</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=1481">24:41</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=14300">3:58:20</a></td>↵
</tr>↵
<tr>↵
<td>[problem:1870E]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=2377">39:37</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=3522">58:42</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=16464">4:34:24</a></td>↵
</tr>↵
<tr>↵
<td>[problem:1870F]</td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=5463">1:31:03</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=10472">2:54:32</a></td>↵
<td><a href="https://youtu.be/9zd9RGqjSfA?t=9037">2:30:37</a></td>↵
</tr>↵
</table>↵
↵
If you open a video and see it's low quality, you might want to wait several minutes until YouTube processes the higher resolutions.
