Middle European Mathematical Olympiad 2013 Problem T-8
The expression is written on the blackboard. Two players, and , play a game, taking turns. Player takes the first turn. In each turn, the player on turn replaces a symbol by a positive integer. After all the symbols are replaced, player replaces each of the signs by either or , independently of each other. Player wins if the value of the expression on the blackboard is not divisible by any of the numbers . Otherwise, player wins.
Determine which player has a winning strategy.