IMC 2012 · Problem 3
Statement
Given an integer , let be the group of permutations of the numbers . Two players, and , play the following game. Taking turns, they select elements (one element at a time) from the group . It is forbidden to select an element that has already been selected. The game ends when the selected elements generate the whole group . The player who made the last move loses the game. The first move is made by . Which player has a winning strategy?
Official solution
Proposed by Fedor Petrov, St. Petersburg State University.