Fill the grid with digits 1-7 (1-5 for the example) so that no digit is repeated within a row or a column, and blacken all the remaining cells of the grid. Numbers outside the grid indicate the sums of continuous number groups encountered in the corresponding directions, in order. A single number in a direction should also be considered as a number group. There must be at least one blackened square between different number groups. The sum information for some rows/columns may be missing.