Normal sudoku rules apply. Chiaroscuro: Shade some cells so that all groups of orthogonally connected shaded cells have an even number of cells and all groups of orthogonally connected unshaded cells have an odd number of cells. Two groups cannot have the same shape and size, counting rotations and reflections as the same. Digits cannot repeat within a Chiaroscuro group. A digit in a circled cell is equal to the size of the Chiaroscuro group which contains that cell. If a cell has a given number in the upper left corner, then the digits in the Chiaroscuro group which contains that cell must sum to that number.