Hello everyone!

I would like to invite all of you to participate in October Circuits '20. It's a coding marathon that opens at Oct 17, 15:30 UTC and runs for 7 days, closing on Oct 24, 15:30 UTC. Please make sure to check your time zones.

The problems were prepared by me. Thanks to Arpa for coordination and MhdMohammadi for testing and haas, Haghani, ... for creating tps and MikeMirzayanov for testlib.h .

Problem statements are short but they contain easy to ignore story parts, the stories are about two character named M and Y:

This coding marathon challenges you with 8 problems. You are expected to solve 7 algorithmic and 1 Approximate programing problem over a period of 7 days.

The timeline of the challenge is as follows:

• Day 0: Problem 1, Problem 2, Problem 3

• Day 1: Problem 4, Problem 5

• Day 4: Problem 6, Problem 7

• Day 6: Problem 8

• Day 7: Challenge ends

New problem statements will be published every 48 hours.

Remember, this is a rated contest and there are amazing vouchers for top three coders.

For more information, visit the contest's official web page.

UPD: There is some defects in some of tests for problems Two paper I and Expectation, I fixed tests but because of incomprehensible hackerearth admins neither me nor Arpa are not allowed to modify tests so the only way is to consider score in problem Two paper I is from 64 and in problem Expectation is 60 (they are all correct), Sorry all.