Insight · ★★★☆☆ · ~7 min
Nim
Piles of stones, take the last to win. There's a binary trick to never lose.
by MindYourPuzzle
A 4,000-year-old game with a solution that looks like magic until you see the binary.
Two players face several piles of stones — say piles of 3, 5, and 6. Players alternate turns. On your turn you remove any number of stones (at least one) from a single pile. The player who takes the last stone wins.
Both play perfectly.
From the starting position (3, 5, 6), is it a win for the player who moves FIRST, or the player who moves SECOND?
(Answer "first" or "second".)
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