In the nurikabe-pair, you need to draw lines (symbolize rivers), so that the table is divided into empty sections with numbers (symbolize islands), observing the following rules:
- The river must be solid, i.e. all colored cells must be connected into a single chain.
- Shaded cells cannot form a 2x2 square (or bigger).
- Each island must contain two numbers, the sum of which is equal to the number of cells on the island.