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 (round INTEGER, res VARCHAR, opponent VARCHAR)
### Question:
Name the Round that has Res of win and an Opponent of demian maia?
### Answer:
SELECT SUM(round) FROM table_name_15 WHERE res = "win" AND opponent = "demian maia"