I need to understand the working of random_row and random_col functions.

```
def random_row(board):
return randint(0, len(board) - 1)
def random_col(board):
return randint(0, len(board[0]) - 1)
```

1. How does the length of Grid calculated? If the Grid is 4*5 (4 rows and 5 columns) then what would be the length?

2. Why are we subtracting the length?

3. In the random_col function why are we including index 0 while subtracting from 1, and doing the same for random_row function?

Thanks in advance for help