Firumatto ("Fillmat") is a logic puzzle published by Nikoli. A rectangular or square grid contains digits in some cells. It is necessary to divide the grid into rectangular regions. Every region must be exactly one cell wide; the other side of the region has length from 1 to 4 cells. A cell with a number indicates the size of a region. Two regions of the same size must not be orthogonally adjacent. 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.