Hello Codeforces

Back from the dead, we'd like to invite you to the online mirror of the Helvetic Coding Contest, Switzerland open championship! You can find past mirror from 2019, 2018, 2017, and 2016.

The Helvetic Coding Contest used to be held yearly at EPFL. This year, the Polympiads association is bringing it back alive! The contest itself took place on April the 13th, but the online mirror is scheduled on Saturday, 4th of May, 90:05 Swiss time. The duration is 4:30.

Rules: * you can participate in teams or individually (1-3 people), * standard ACM-ICPC rules (no hacking), * the contest is not rated, * if you have participated in the onsite contest, please do not participate in the mirror.

Contrary to what the mirror might lead you to believe, this year's theme is Harry Potter. It features 7 series of 3 related tasks with increasing difficulty (easy/medium/hard).

Thanks a lot to: * Petr, Charbel, ScarletS, 3EVEHAR_KOAVA, AdrienVannson, bjornargh, and zehnsechs for setting and/or coordinating the problemsetting, * matrix for preparing the technical setup of the contest * paula, Macdu, McLovinn as well as problemsetters for testing the contest, * All of Polympiads committee and on the day staff for making the contest possible, * MikeMirzayanov for creating the amazing Codeforces and Polygon platforms!