**October Lunchtime** starts in just under 24 hours, and I am the editorialist for the whole contest.

This time, problems are especially interesting for me. Big thanks to **Pavel Sheftelevich**, who created all of them. Pavel has a great ability to create incredible problems with really simple statements - the thing we all love. The setter of a previous Lunchtime, **Sergey Kulik,** is the tester of the whole problem set this time. We started working on this contest later than usual, but it turned out, that a great contest can be prepared in just a few days

If you decide to participate, which you should do, you will probably start with solving two simple problems: an easy string problem and an interesting one ad-hoc problem related to multiplication extremely big numbers. For those of you who managed to solve them quickly, there are two harder problems waiting. I can tell you, that a desired solution to one of them uses a technique, which is not known as much as it should be. I will describe the approach with details, in the editorial, which will be posted just after the contest on Codechef discuss. The last subtask to the second of these harder problems, at first time might look unsolvable for some participants, but I really encourage all of you to engage all of your skills to solve it. If you manage it, you will be very pleased

See you on Leaderboard!

**UPDATE:**

All editorials are available here