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_23157997_13 (mountains_classification VARCHAR, youth_classification VARCHAR)
  ### Question:
  How many Mountains Classifications were in the race with Mike Northey as Youth Classification?
  ### Answer:
  SELECT COUNT(mountains_classification) FROM table_23157997_13 WHERE youth_classification = "Mike Northey"