Color each square white or black.
Click to blacken a square,
click again to white it, again to re-gray it.
(or shift-click to white);
The numbers indicate how many white squares
can be 'seen' horizontally and vertically from the cell.
Cells see themselves. They do not see thru black square.
All white cells must be connected
as a single polyomino -
a continuous path attached at edges
Each black cell MUST be isolated
from other black cells (not attached at edges).