user: Question: How many different episode numbers are there for the episodes directed by Sheri Elwood?
Columns: ['Total #', 'Episode #', 'Title', 'Directed by', 'Written by', 'Original air date']
Types: ['real', 'real', 'text', 'text', 'text', 'text']
Sample row: [14.0, 1.0, '"Ass Hickey"', 'James Genn', 'Sheri Elwood', 'September25,2011']
SQL:

assistant: SELECT COUNT("Total #") FROM "Table" WHERE "Directed by" = 'Sheri Elwood';