Normal sudoku rules apply. Yin Yang: Shade some cells such that all shaded cells are orthogonally connected, all unshaded cells are orthogonally connected, and no 2x2 area is fully shaded or fully unshaded. Shaded cells act as fortress (maximum) cells: shaded cells must be larger than all orthogonal neighbors of the cell that are unshaded. A digit in a cell with an arrow counts the total number of shaded cells seen in the direction of the arrow (not counting the cell itself).