Grid A Grid BA 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.*