Sudoku: Fill all rows, columns and marked 3x3 boxes with the digits 1-9 without any repeats. Chaos Construction: Divide the grid into 9 additional regions of 9 orthogonally connected cells. Each extra region contains the digits 1-9 without repeats. Circles: A digit in a circle indicates how many cells (including itself) overlap between its 3x3 box and its additional region.