Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_31476 ( "Round" real, "Circuit" text, "Date" text, "Length" text, "Pole Position" text, "GT3 Winner" text, "GT4 Winner" text )

### Question ###
When david ashburn richard westbrook is the gt3 winner and 1 is the round what is the length?

### Accurate SQL ###

SELECT "Length" FROM table_31476 WHERE "Round" = '1' AND "GT3 Winner" = 'David Ashburn Richard Westbrook'