Normal sudoku rules apply. Digits in cells marked in red in columns 1, 5 and 9 indicate the position of the 1, 5 and 9 respectively in the corresponding row - all possible red cells are given. All cages must contain digits which sum to the same total, which must be determined by the solver. Digits cannot repeat in the same position in different 3x3 boxes, e.g. if 5 is in row 1 column 1, it cannot appear in row 4 column 4.