- The first few lines represent the input board, followed by a line containing -------, which acts as a separator, followed by several lines where each line represents one subgrid and related constraints 
- Each of the lines representing the input board will have space-separated integers ranging from 0-n, where n is the size of the square board
- 0 denotes empty cells, 1-n denotes an already filled cell
- After the board, there is a separator line containing -------
- Each of the following lines has space-separated elements representing the subgrids on the input board, the operations for each of the subgrids and their expected results 
- Each of these lines has integers representing cells of a subgrid followed by a character representing the operation followed by the expected result
- 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
- The operation can be one of the following: + for addition, * for multiplication, % for division, - for subtraction or ? denoting that the subgrid is of size one and the result for this subgrid is the value of the singular cell of that subgrid
- % and - will only be used with subgrids of size 2, ? will only be used with subgrids of size 1