- 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
- Each of the lines representing the input board will have space-separated integers ranging from 0 to 3
- 0 denotes empty cells, 1 denotes a filled cell (blackened cell), 2 denotes a cell with a balloon,  3 denotes a cell with an iron ball
- 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
- Each of these lines has integers representing cells of a subgrid
- 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