Welcome to an all-new contest series on LMI, Puzzle Train. The first journey will take participants through a set of Tapa puzzles. If you are unsure what Tapa is, check out the about page for rules and explanations. The joyful ride begins on 25th December 2021 at 8:00 AM IST with the first official puzzle and then a new puzzle releasing every 30 hours. The final official puzzle will be released on 13th January 2021 at 2:00 AM IST. There will be 21 puzzles, with the first five being trial puzzles, after which the actual contest will begin, containing 16 puzzles. Some of the trial puzzles are already available for you to try. The order of puzzles is not necessarily according to difficulty. Please read the following rules carefully.

Participation:

1. Participants must solve within the 30-hour window of the puzzle to be considered for the official ranking of that day (i.e., the submission must be before the 30-hour window ends).
2. Participants can still solve the puzzle outside the official window but won't be awarded any points for that day.
3. The contest page will show which puzzle is active at any given moment.
4. Click on the "Start" button to start the puzzle. A new window will open. The puzzle page does not contain rules.
5. If you prefer a different display size, the participant can resize the puzzle using the “Resize” button -> Display size -> Apply Changes.
6. The default mode is set to "Surface" for shading, but solvers can go to "Settings" and turn OFF Penpa-lite to access other modes.
7. Once the solver thinks they have reached a solution, they must click the "Submit Solution" button at the bottom of the grid.
8. Instant grading is enabled. If the solution is correct, a pop-up will appear saying so, and the player can rate the puzzle and provide any feedback, which will appear on the discussions page. Next, there will be a link to go back to the contest page.
9. A penalty of "2" minutes is added to solving time for each wrong submission.

Features:

Once the participant has successfully solved the puzzle, the following will be available on the contest page:

1. Ratings – Participants can rate each puzzle.
2. Discussion – Participants can share comments or discuss the puzzle on the "Standings/Feedback" page. Each puzzle has its own discussion page.
3. Replays – Participants can check out other players' solution approaches by clicking on "Standings" and then clicking on individual times.