Hello, codeforces!

It's been awhile since 20th of June, when all tasks, test cases, and sample solutions from the first phase of Brazilian Olympiad at Informatics (OBI) were released in their official website. Since then, the time for submitting issues about the contest is gone as well.

Until now, it is not of my knowledge that the tasks are available for submitting anywhere online. That's why I decided, with the help of my friends eduguibar and gpribeiro, to translate the statements and to publish them here. This way, we can submit :), help others friends that are in the same situation, and possibly allow a broader public to try the tasks.

You can try the tasks here. Also, if you want to compete in some way, you can take virtual participation. The olympiad is not done this way, so the time of 3 hours is arbitrary, and maybe we should change it in the future.

Thanks to the people who make OBI this great olympiad, to all my friends at CP for the support, and to Mike Mirzayanov for the amazing codeforces and polygon platforms.

Disclaimer:

• These tasks were presented in different contests based on the classes of the participants. This contest is a merge of all different questions that appeared, and you can find the different versions at the statements sections (in portuguese).

• Since this is the first phase of the olympiad, the tasks would be too easy for experienced users.

• My english is far from perfect, and this is the first time I use polygon. So, when you find some mistakes, please point that to me, I will be happy to change them.

• I don't have any link with the olympiad and didn't find anywhere that I couldn't do this. But if there is some problem, feel free to contact me and I will take this down immediatly.