input: Write a python function to parse a string of words and numbers separated by commas.
  assert parse_string('apple,10,cats,20') == (['apple', 'cats'], [10, 20])
  assert parse_string('dog,30,banana,40,car') == (['dog', 'banana', 'car'], [30, 40])
  assert parse_string('50,table,60,chair,70') == (['table', 'chair'], [50, 60, 70])
output: def parse_string(s):
      words = []
      numbers = []
      for item in s.split(','):
          if item.isdigit():
              numbers.append(int(item))
          else:
              words.append(item)
      return words, numbers