Raneko ("Ranekomappu"; from Japanese, literally "cat habitat map") is a logic puzzle published by Nikoli. A rectangular or square grid contains circles (with numbers or empty). The goal is to divide the grid into regions. Each region contains one circle ("cat"). A circle with a number indicates the size of a region. A grid may contain black cells. The number in a black cell indicates how many regions share an edge with that black cell.
Cross+A can solve puzzles from 3 x 3 to 30 x 30.