# Threatened Rooks

Find the largest number of rooks that can be placed in a $$3000 \times 3000$$ chessboard in such a way that each rook is threatened by no more than one rook.

Details and Assumptions:

• Rooks can attack in any range but can only attack in a horizontal or vertical direction.
• A rook is considered to be "threatened" if another rook can attack it.
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