- The first n lines represent the input board
- Each of the first n lines has n space-separated integers ranging from 0-n
- 0 denotes empty cells, 1-n denotes an already filled cell
- Each of the following lines has space-separated integers representing the subgrids on the input board and their expected products 
- Each of these lines has integers representing cells of a subgrid followed by an integer representing the subgrid product
- Cells are numbered in row-major order starting from 0, and this numbering is used to represent cells in each of the lines describing the subgrids