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"