Renban consists of a square grid divided into regions. The aim is to fill in each cell with numbers from 1 to N, where N is the size of the puzzle's side. No number may appear twice in any row, column or region. All numbers in a region must form a sequence of consecutive numbers, but in any order (for example: 5-3-4).
Cross+A can solve puzzles from 4 x 4 to 9 x 9.