Fill your information and click "Sign up".
User ID is your handle used in this website.
It should consist of letters, digits, and underscores, and the length should be between 3 and 16, inclusive.
User name is currently not used, but we recommend to fill it with the same string as User ID.
Click "Join in AtCoder Grand Contest 001".
(You can do this during the contest, but we recommend you to do it before the contest to save your time.
Your rating will not change if you don't submit anything during the contest.)
When the contest starts, go to the contest website and solve problems!