My Telegram: https://t.me/rembocoder
The problems:
https://codeforces.com/contest/1801/problem/A
https://codeforces.com/contest/1801/problem/B
https://codeforces.com/contest/1801/problem/C
https://codeforces.com/contest/1801/problem/D
The solutions:
https://codeforces.com/contest/1801/submission/196665256
https://codeforces.com/contest/1801/submission/196667482
https://codeforces.com/contest/1801/submission/196670147
https://codeforces.com/contest/1801/submission/196678364
0:00 Statement A
0:47 Solution A
4:03 Code A
4:24 Statement B
5:18 Solution B
9:01 Code B
10:51 Statement C
11:25 Solution C
17:20 Code C
19:23 Statement D
20:07 Solution D
24:35 Lemma
26:55 Back to solution D
28:22 Code D
