Grid A Grid B A B C D A B C D +---+---+---+---+ +---+---+---+---+ 1 | | | | | 1 |14 |23 |34 |14 | +---+---+---+---+ +---+---+---+---+ 2 | | | | | 2 |31 |42 |26 |26 | +---+---+---+---+ +---+---+---+---+ 3 | | | | | 3 |22 |24 |44 |29 | +---+---+---+---+ +---+---+---+---+ 4 | | | | | 4 |12 |32 |19 |16 | +---+---+---+---+ +---+---+---+---+
The number in each cell of grid B is the sum of the horizontal and vertical neighbors of the corresponding cell in grid A.
NB. The letters and numbers around the edge of the grid serve no purpose for the solver. They are to be used for identifying cells in the solution.