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_15 (sets_lost VARCHAR, sets_won INTEGER)
### Question:
How many sets lost have a sets won less than 0?
### Answer:
SELECT COUNT(sets_lost) FROM table_name_15 WHERE sets_won < 0