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 (round VARCHAR, winning_manufacturer VARCHAR, circuit VARCHAR)
### Question:
What was the final number for the winning manufacturer with Mercedes-benz, and a circuit of hockenheimring?
### Answer:
SELECT COUNT(round) FROM table_name_18 WHERE winning_manufacturer = "mercedes-benz" AND circuit = "hockenheimring"