Usotatami is a logic puzzle published by Nikoli. A rectangular or square grid contains numbers in some cells. The aim is to divide the grid into rectangular regions such that each region contains exactly one number. Every region must be exactly one cell wide; the length of the other side is NOT equal to the number in this region. A grid dot must not be shared by the corners of four regions.
Cross+A can solve puzzles from 3 x 3 to 30 x 30.