Make a team account, which you will use for the exam.
You can explore the site with your team, and find out how it works, how to submit the code, etc.
Read the rules before the final contest.
Solve the problem I've kept here. It's quite easy.
If you still don't know how to solve these type of problems, please contact your subject teacher ASAP.
WARNING: Plagiarised code is automatically detected by the judge.