A and b? People play the following games:

Take a big chocolate with five horizontal lines and nine vertical lines. These lines divide chocolate into 60 cells.

A first break the chocolate into two pieces along a line and eat L pieces (the two pieces are not necessarily equal); B Break the remaining chocolate into two pieces along a line and eat 1 piece. In this way, two people take turns to break chocolate until there is a small box of chocolate left. The winner is the last person to leave a small box.

Q: Can A and B have a strategy of winning every battle?

It is not easy to answer this question, but we can consider simple questions first. If the chocolate is long, (such as 1? Who has a winning strategy?

Obviously, A won. Because he can put. 5 grams of force broke off 9 squares, leaving 1 square.

If the frame of chocolate is 2? 2, then the person who takes it first can't win. Because no matter how he broke off, he could only leave 1. Two pieces of chocolate.

To sum up, if chocolate is 2? 2 squares, B wins.

If chocolate is 2? C (C is not 2), then A wins.

If you think about it carefully, you can find: if chocolate is a square a? One grid, the last one wins; If the chocolate is not square, whoever gets it first wins.

So, six? 10 cube of chocolate, A can win forever. His strategy is to turn chocolate into a square every time.