Codeforces Round 668 Stream + All Div. 2 Solutions (2A-E, 1A-C) (+ duels, + extra)

Join this discord to find out when more streams will happen (because of school, they're definitely going to be inconsistent):   / discord  

Contest link (Div. 1): https://codeforces.com/contest/1404
Contest link (Div. 2): https://codeforces.com/contest/1405

For the sidebar: my school is hosting a tournament for CP, basically like the rounds you guys are used to! Our website is at https://mbit.mbhs.edu/ and registration will open soon.

Starting 00:00
2A solving + solution 08:19
Misreading 2B 10:57
Actually solving 2B + solution 14:20
2C solving + solution 20:49
Slowly proving 2D (+ solution) 35:07
Writing code for 2D 1:08:10
2E solving + solution 1:16:35
Lazily attempting 1D (didn't really get anywhere) 1:41:02
Awkward pause before starting duels 2:01:54
Duels 2:25:22
Not realizing my mic is muted 3:41:45
Random stuff 3:46:45