**Foseruzu** (*"Four Cells"*) is a type of logic puzzle published by Nikoli. The goal is to divide the grid into regions of exactly four cells. The number inside a cell represents how many of its four sides are segments of region borders (including the border of the grid).

**Cross+A** can solve puzzles from **3 x 3** to **30 x 30**.

**Faibuseruzu** (*"Five Cells"*, *"Solomon's Keep"*): the grid needs to be divided into regions of exactly five cells.