user: Question: How many writers were there in the episode directed by Charles Haid?
Columns: ['Episode #', 'Title', 'Directed by', 'Written by', 'Original air date', 'Viewers (in millions)']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '"Pilot"', 'Michael Dinner', 'Vincent Angell, William Rotko', 'January15,2009', '2.45']
SQL:

assistant: SELECT COUNT("Written by") FROM "Table" WHERE "Directed by" = 'Charles Haid';