How to read the clues
3 means three filled squares together.
1 · 1 means one filled square, a gap, then one more.
Unknown
■Filled
×Known empty
Select a square to cycle it: unknown → filled → known empty → unknown. The clues list filled runs in order, with at least one empty square between separate numbers.
Start with the longest clues. A clue of 5 fills the whole line.
Game manual