Challenge24 had been started as an internal competition at the local techincal university of Budapest. For now it became an international programming contest which is being organized 8th time this year. The contest itself usually happens in May when teams must be present personally but it's preceeded by a qualifying session (a.k.a Electronic Contest ) which has been arranged on the last weekend of February and teams didn't have to be present personally, just to be online. At Electronic Contest there are up to 8 combinatorical, geometrical, game theorical problems which have to be solved by sending the result files to the central server. Teams are free to choose platform and programming language. More information including rules, list of teams and their scores, assignment of the Electronic Contest can be found on the homepage . The name is Challenge24, because the main contest in May lasts for 24 hours. I didn't take part nor this year nor earlier but I usually download and