Divide the grid into regions and place a number in each cell. The numbers within a region must all be the same and equal to the size of the region. Regions of equal size must not touch orthogonally, but may touch diagonally. A region may contain zero, one or more of the given numbers. In addition, it must be possible to shade some regions fully, such that two shaded regions or two unshaded regions never touch orthogonally.