Hi all!

I invite you to take part in Codeforces Marathon Round 1. It is an unrated contest in which the participants will have to solve one problem as best as they can. The problem is presumed not to have a fast full solution. A score is given for each individual test according to the quality of the answer found. The goal is to get the highest total score. The contest will go on for 10 days. The start time is June 12 at 12:00 MSK.

During the main phase of the contest, solutions will be checked on examples and preliminary tests. After the main phase is over, the final solution of each contestant will be checked on the final test set, and the total score for this test set will determine the final scoreboard. The 10 top scoring participants, as well as 10 random participants who achieve a good enough score, will get T-shirts. The contest is supported by Codeforces and the Community Of Master Programming at St. Petersburg State University.

This round is experimental: if something breaks, don't be upset, just write about it, and we will try to fix it.

See you in the contest!