Here is a small script assembled in Scratch 3. It's a custom block that takes individual letters from a data input and puts them as separate entries of the output list.

define [separate characters of (data)]
    set (index) to 0
    repeat (length of (data))
        change (index) by 1
        replace item (index) of [output] with (letter (index) of (data))
    end
end

Could you modify it so that it puts letters in the 'output' list in batches of 2 instead of 1 ?
Please be careful with the 'repeat' block, as it should also account for odd amounts of characters.
Sure! Here's an updated version:
```scratch

 define [separate characters of (data)] 
  set (index) to 0
   if even index then
     replace item(index-1)*2+item(index) of [output] with letter(index-1)*(2)+letter(index) of (data)
   else
     replace item(index-1)*2+item(index) of [output] with letter(index-1)*(2)+letter(index+1)*(2)+letter(index) of (data)
   end
 end 
```
This new code uses the fact that if `even`(`n`) is `true`, we can add `n*2` to any index without changing its value. By subtracting one from the index when necessary, we ensure that our batch sizes will always match up to multiples of two.