user: Question: How many directors worked on #158?
Columns: ['Series #', 'Season #', 'Title', 'Director', 'Writer(s)', 'Airdate']
Types: ['real', 'real', 'text', 'text', 'text', 'text']
Sample row: [157.0, 1.0, '" Target "', 'Andrew V. McLaglen Category:Articles with hCards', 'John Meston Category:Articles with hCards', 'September 5, 1959']
SQL:

assistant: SELECT COUNT("Director") FROM "Table" WHERE "Series #" = 158.0;