Neibadomino ("Neighbour Domino") is a logic puzzle invented by Naoki Inaba (Japan). A rectangular or square grid contains numbers in some cells. The aim is to locate some blocks in the grid, having the size of exactly two cells ("dominoes"), and fill blocks with numbers. The grid may contain cells that belong to no one block. Each number in the grid should be part of a block, indicating the amount of orthogonally adjacent dominoes. Blocks with the same numbers must not be orthogonally adjacent. Blocks must not cover an area of 2 x 2 cells. (The grid may contain 2 x 2 cell area without blocks.)
Cross+A can solve puzzles from 4 x 4 to 30 x 30.