text: Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
  ### Context:
  CREATE TABLE table_28081876_4 (written_by VARCHAR, directed_by VARCHAR)
  ### Question:
  how many people wrote the episode directed by rob schrab?
  ### Answer:
  SELECT COUNT(written_by) FROM table_28081876_4 WHERE directed_by = "Rob Schrab"