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_name_18 (frequency__per_hour_ VARCHAR, line VARCHAR, destination VARCHAR)
  ### Question:
  How many frequencies have a line of East London and destination of Crystal Palace?
  ### Answer:
  SELECT COUNT(frequency__per_hour_) FROM table_name_18 WHERE line = "east london" AND destination = "crystal palace"