Запрос на слияние 'second' (#1) из second в master

update README.md

update README.md

upload files

upload files

update README.md

update README.md

upload files

upload files

create demo/artifacts.md

upload files

create dev/solution.py

test

upload files

create dev/solution.py

update spec/codex.md

upload files

create spec/codex.md