747 Take-off
- Regions to construct
- Chaos construction
The brief
- Chaos Construction: Divide the grid into seven orthogonally connected seven-cell regions, and place the digits 1-7 once in each row, column, and region.
- Circles: The four cells around an circle must either all belong to one region or all belong to different regions.
- Target Sums: A clue X outside the grid indicates the sum of all the digits that appear in its row or column before reaching the target digit X (starting from the end with the clue).
- Indicated Region Borders: For each outside clue, the digits in the sum must belong to the same region and the digit X must belong to a different region.