Normal sudoku rules apply. Colour every cell in the grid in one of two colours such that the cells of each colour are orthogonally connected and no 2x2 area is entirely one colour. The grey ring in the grid must be divided into non-overlapping groups of cells along the ring that sum to 10. Digits may repeat within a group. (NB These groups must be contiguous along the line but need not be orthogonally connected.) Additionally, each of the groups along the line that sum to 10 must all be one colour and two adjacent groups cannot be the same colour.