Colour some squares black, so as to meet the following conditions:

- No two black squares are orthogonally adjacent.
- No group of white squares is separated from the rest of the grid by black squares.
- Each numbered cell can see precisely that many white squares in total by looking in all four orthogonal directions, counting itself. (Black squares block the view. So, for example, a 2 clue must be adjacent to three black squares or grid edges, and in the fourth direction there must be one white square and then a black one beyond it.)

Left-click to colour a square black. Right-click to mark a square with a dot, if you know it should not be black.