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_68 (year INTEGER, entrant VARCHAR, chassis VARCHAR)
### Question:
What was the sum of the years, when the entrant was Scuderia Ferrari, and when the Chassis was Ferrari 312/66?
### Answer:
SELECT SUM(year) FROM table_name_68 WHERE entrant = "scuderia ferrari" AND chassis = "ferrari 312/66"