- ➊ Write exactly one number from the given Range into some
cells of the diagram so that a number occurs at most once in each row and
- ➋ Blacken the remaining cells. The black cells separate the
the rows and columns into groups of numbered cells.
- ➌ The numbers on the top and left edge of the diagram denote
the sums of the numbers in these groups in order from left to tight and from
top to bottom.