[Arkshine]

Changing 33 to 32 is not an optimization. It's more convenient to use 33 and less ugly so you don't have to do the "-1" operation each time, which can be lead to errors. It doesn't matter to add an extra cell and can be useful sometimes to have the 0 as index.
Also, I don't understand your packed data thing. You create more code just for reducing a bit the memory used -> not worth for this case. Generally you would optimize the code for speed, not for memory.
But here, that's not about memory or speed, but more about code design.