Time: 15:04

## Competition rules

- Participants compete in teams of up to 3 members.
- At least one member has to have a Školjka account.
- The contest has a large number of problems organized in
*chains*, with 5 problems per chain at most. - For every chain, only the first problem is unlocked at the beginning of the contest. By solving the first problem, the second one is unlocked and so on.
- The contest starts with only some chains visible. As the contest progresses, new chains are made available.
- Every problem is worth 1 point, unless specified otherwise.
- By solving a complete chain, the team is awarded additional bonus points shown at the right of the chain. Typically the bonus is equal to 1 point.
- In each problem, a solution in a form of a number, word, list of numbers or similar is required. The required format will be explained in details in problem description.
- Every team has 3 attempts to solve each problem. If three incorrect attempts are made, the team won't be able to score the points for that problem. However, the next problem, if it exists, does unlock. Note that the chain bonus points are awarded only if all problems of a chain are correctly solved.
- Please take notice on the required format when submitting a solution. If you think you accidentally entered the result in the wrong format and it was not accepted, send a message by clicking on Notifications in the menu. If the organizers determine that it was indeed a format error and not an incorrect result, and if this was not the 3rd attempt that unlocked the next problem, the organizers will cancel the submittion.
- The majority of the problems can be solved with pen and paper, but some may require the usage of calculators or computers.
- Communication with other teams for the purpose of exchanging problem-related ideas and solutions is not allowed. Cheating in any other way is as well not allowed.

### Solution format description

Integer | A simple number, positive or negative. In general, all numbers mentioned below can be positive or negative. |

Decimal number | The solution must have as least as many decimals as written in the description, and has to exactly match the official solution when rounded to that number of decimals. |

Fraction | Fractions are written in the format a/b, where a and b are integers. Reducible fractions are accepted. You can also write a single integer if you are sure the result is an integer. Decimal numbers are not accepted. |

List | A list can contain integers, decimal numbers, fractions or strings (anything else). If not obvious, the type of elements will be specified, together with the decimal count in the case of decimal numbers. The length of the list might or might not be specified. The list can also contain a single element! Separate the elements with a comma. |

Set | Same as for lists, just the order does not matter. |

String | Anything that does not match any other type. That can include words, special formats, or even numbers of special forms. |

Textual | Textual answer, manually graded by the organizers. |