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_29 (laps INTEGER, grid VARCHAR, driver VARCHAR)
### Question:
what is the sum of laps when grid is less than 20 and johnny herbert is driving?
### Answer:
SELECT SUM(laps) FROM table_name_29 WHERE grid < 20 AND driver = "johnny herbert"