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_19526911_1 (arena__capacity_ VARCHAR, head_coach VARCHAR)
### Question:
What is the arena capacity of the arena in the town whose head coach is Roberto Serniotti?
### Answer:
SELECT arena__capacity_ FROM table_19526911_1 WHERE head_coach = "Roberto Serniotti"