Normal sudoku rules apply. Yin Yang Yong: Colour the grid red, yellow and blue, so that all cells of the same colour are orthogonally connected, and no 2x2 area is fully one colour. A red cell's value = double its digit. A yellow cell's value = its digit. A blue cell's value = half its digit. Clues outside the grid give the total value of the indicated row or column. A blue line joins two cells with the same value.