What is the arena capacity of the arena in the town whose head coach is Roberto Serniotti?
CREATE TABLE table_23068 (
    "Previous season 2007/2008" text,
    "Team" text,
    "Town" text,
    "Arena (capacity)" text,
    "Website" text,
    "Head Coach" text,
    "Foreign Players (max. 2)" text
)
SELECT "Arena (capacity)" FROM table_23068 WHERE "Head Coach" = 'Roberto Serniotti'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What is the arena capacity of the arena in the town whose head coach is Roberto Serniotti? ### Input: CREATE TABLE table_23068 (
    "Previous season 2007/2008" text,
    "Team" text,
    "Town" text,
    "Arena (capacity)" text,
    "Website" text,
    "Head Coach" text,
    "Foreign Players (max. 2)" text
) ### Response: SELECT "Arena (capacity)" FROM table_23068 WHERE "Head Coach" = 'Roberto Serniotti'