Proper noun
the Josephus problem
(mathematics) A theoretical problem in which every nth person, counting around a circle of people, is chosen for execution, and this process repeats after the removal of each chosen person, with the last person left being freed. The problem is to select one's position so as to be the last to be chosen.
The Josephus problem is an election method that works by having a group of people stand in a circle. Source: Internet