Four Fours
- Arrows
- Region sum lines
- Whisper lines
The brief
The puzzle grid is made up of four 4*4 sudokus. In each sudoku, enter 4 of the digits 1-9 in each row, column, and 2*2 region. Digits cannot repeat in any row or column in the 8*8 sudoku grid.
Digits on an arrow sum to the number on that arrows circle.
Digits on a green German Whisper line must differ by at least 5.
Digits on a blue region sum line have the same sum in each 2*2 box it passes through.
