Cross The Streams/en
Aus Puzzlewiki
Instructions
Shade in some cells black such that the black cells are all connected to each other through their edges, and no 2x2 cell area within the grid contains all black cells. Numbers to the left of a row or above a column represent the groups of consecutive black cells which are in that row or column. For example, a clue of "3" means the row or column has three consecutive black cells, and a clue of "3 1" means that the row or column has a group of three consecutive black cells followed by a single black cell, separated by at least one white cell.
A question mark (?) represents a group of consecutive black cells whose size is unknown; an asterisk (*) represents any number of unknown groups of black cells, including none at all.