code: def get_pallete_length(grid):
      
      elements = list(set(flatten_array(grid)))
      length = len(elements)
  
      if type(elements[0]) is str:
          lengths = [len(el) for el in elements if not el.startswith("-")]
          if max(lengths) < 5:  # Mixing red and green
              length += 2  # is not pretty so let's avoid it
      return length
docs: Takes a 2d grid and figures out how many different elements are in it, so
      that we know how big to make the palette. Also avoids the unfortunate
      red/green palette that results from too few elements.
  
      Returns int indicating the length the palette should have.