Shade cells so each number sits in a white island with exactly that many cells.
Every island holds exactly one number.
All shaded cells form one connected sea, with no 2 × 2 block fully shaded.
The Islands (1, 2, 3, and 4)
Each number sits in a white island with exactly that many cells. Islands never touch along a side.
✓ Correct
Islands of sizes 1, 2, 3, and 4. Every island has its exact number of cells and is isolated by the sea.
✗ Wrong
Islands 1 and 2 touch along a side. Islands cannot share an edge and must be separated by shaded cells.
✗ Wrong
Island 3 has only 2 cells. Every island must contain exactly its given number of cells.
The Sea (no 2x2 and connected)
All shaded cells form one connected sea, with no 2 x 2 block fully shaded.
✓ Correct
The shaded sea forms one single connected group, with no 2x2 square of shaded cells anywhere.
✗ Wrong
A 2x2 block of shaded cells. The sea cannot contain any fully shaded 2x2 square.
✗ Wrong
Disconnected sea: the shaded cell in the top-left corner is cut off from the rest of the sea.
Shade cells so each number sits in a white island with exactly that many cells.
Every island holds exactly one number.
All shaded cells form one connected sea, with no 2 × 2 block fully shaded.
The Islands (1, 2, 3, and 4)
Each number sits in a white island with exactly that many cells. Islands never touch along a side.
✓ Correct
Islands of sizes 1, 2, 3, and 4. Every island has its exact number of cells and is isolated by the sea.
✗ Wrong
Islands 1 and 2 touch along a side. Islands cannot share an edge and must be separated by shaded cells.
✗ Wrong
Island 3 has only 2 cells. Every island must contain exactly its given number of cells.
The Sea (no 2x2 and connected)
All shaded cells form one connected sea, with no 2 x 2 block fully shaded.
✓ Correct
The shaded sea forms one single connected group, with no 2x2 square of shaded cells anywhere.
✗ Wrong
A 2x2 block of shaded cells. The sea cannot contain any fully shaded 2x2 square.
✗ Wrong
Disconnected sea: the shaded cell in the top-left corner is cut off from the rest of the sea.
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