题目是这样的：
There are 12 toothpicks arranged in 3 rows of 5, 4, and 3 toothpicks each as shown
below.
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There are two players, player A and player B. Player A moves first and must take one or
more toothpicks from only one row. Then player B must do the same. The players take
turns until one player is left with only one toothpick. That player loses and gets a payoff
of 0. The other player wins and gets a payoff of 1.
Draw the Extensive form for this game.

跪谢各位大虾~~~~！~~~~