Question 67
Players $A$ and $B$ play a game: given a positive integer $n$, one has to choose a divisor $m$ of $n$ which is greater than $1$ and smaller than $n$ and replace $n$ with $n - m$. Player $A$ makes the first move, players move alternately. The player who can't make a move loses the game. For which starting positive number $n$ player $B$ has a winning strategy?