Please watch! https://youtu.be/4B3g4NLdbuA↵
↵
I've solved and explained all five problems of [contest:1977], the video will appear in about an hour.↵
↵
UPD: the video is available.
↵
I've solved and explained all five problems of [contest:1977], the video will appear in about an hour.↵
↵
UPD: the video is available.