Normal sudoku rules apply. Shade some cells so that the outside clues indicate the sums of the contiguous shaded cells in that row or column. A number indicates the sum of a complete contiguous block. A question mark (?) indicates that a contiguous block sum to a single-digit number and a double question mark (??) indicates that a contiguous block sums to a double-digit number. An asterisk implies that any number of blocks may exist, including zero. The clues are provided in the correct order (left-to-right, or top-to-bottom), and there is at least one unshaded cell between each pair of clued blocks. The shaded cells form a single orthogonally connected group. No 2×2 area within the grid can be totally shaded.