Normal sudoku rules apply. Divide the digits from 1 to 9 into two teams such that every digit from 1 to 9 is in exactly one of the two teams. Thereby, the finished grid has areas (of orthogonally connected cells) which contain only digits from one team and are bounded by digits of the other team and/or the border of the grid. A number clue gives the sum of all the digits in such an area. Digits may repeat in such an area and the sum clues are in an arbitrary position within the area. Each area has at most one clue, but may also have none at all.