text: # Python - 3.6.0
  
  def micro_world(bacteria, k):
      mark = set()
      bacteriaSet = set(bacteria)
      for i, bi in enumerate(bacteriaSet):
          for j, bj in enumerate(bacteriaSet):
              if (i != j) and (not bj in mark) and (bj < bi <= (bj + k)):
                  mark.add(bj)
      return len([*filter(lambda b: not b in mark, bacteria)])
  