The following rules determine which cells are which:
• Each number on the board represents the number of white cells that can be seen from that cell, including itself. A cell can be seen from another cell if they are in the same row or column, and there are no black cells between them in that row or column.
• Numbered cells may not be black.
• No two black cells may be horizontally or vertically adjacent.
• All the white cells must be connected horizontally or vertically.