Winning Strategy for the Rock-Taking Game: Mastering the Art of Leaving Multiples of 3

Question)
There is a pile of 11 rocks. Two players take rocks from the pile in turns. In each turn a player can either take one or two rocks from the pile. The player that takes the last rock wins the game. You move first.

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Answer)

You need to play in such a way that you maintain the strategy of leaving a multiple of 3 for the opponent.

ex)

1. You Take two rocks
2. Your opponent Take two rocks
3. You Take one rock
4. Your opponent Take two rocks
5. You Take one rock
6. Your opponent Take two rocks
7. You Take one rock

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