Question 25
In a game, Alvin and Benny take turns in painting a rectangle in the diagram below. When a rectangle is painted, then all rectangles adjacent to it can no longer be painted. The player who cannot make a move loses the game. For example, if Alvin paints the rectangle $a$ first and Benny paints the rectangle $e$, then Alvin cannot paint any other rectangle anymore. Thus Alvin loses. If Alvin wants to win the game, then what rectangle must he paint first?
