In this puzzle, your goal is to place light bulbs on the grid so that all white squares are illuminated. Follow these placement rules:

1. Light bulbs can only be placed on white squares, not on black squares.

2. A black square with a number indicates how many light bulbs must be placed directly adjacent to it (above, below, left, or right). For example, a black square with "2" must have exactly two adjacent light bulbs. A "0" means no bulbs can be placed next to it. If a black square has no number, any number of bulbs (0 to 4) can be placed around it.

3. Light bulbs shine in straight lines vertically and horizontally but cannot pass through black squares—their light stops at the black square, similar to a rook's move in chess.

4. Light bulbs cannot illuminate other light-bulbs.

5. Every white square must be illuminated by at least one light bulb.

Click on a white square to place or remove a light bulb.

Click the up arrow icon to hide these instructions.