Author/Opus: This is the 263rd puzzle from our contributing puzzlemaster Serkan Yürekli.
Rules: Standard Cross the Streams rules. Also, the shaded region must be able to be split into tetrominoes to form a valid LITS solution (meaning all tetrominoes are connected but no two tetrominoes sharing an edge are the same shape, including rotations and reflections).
Answer String: Enter the length in cells of each of the black segments from top to bottom for the marked columns, going in order from A to B to C to D and separating each entry with a comma.
Time Standards (highlight to view): Grandmaster = 4:45, Master = 7:30, Expert = 15:00.
Note: Follow this link for variations of Cross the Streams and this link for other classic Cross the Streams. If you are new to this puzzle type, here are our easiest Cross the Streams to get started on.