KöMaL 2026 B5532

An opera house has 8 boxes. With a box subscription, one can reserve the same box for at most 7 different evenings of the 2027/28 season, chosen by the buyer. There is one performance each evening. A box can be rented by only one person for a given evening, but multiple subscriptions may refer to the same box as long as the sets of selected evenings are disjoint. What is the minimum number of different performances in the repertoire such that the opera house can always arrange the program (knowing the subscribers' chosen dates) so that every box subscriber sees only different performances?