user: Question: When 6.66 is the amount of viewers what is the lowest production code?
Columns: ['#', 'Title', 'Director', 'Writer(s)', 'Viewers', 'Air date', 'Production code']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'real']
Sample row: [1.0, '"Pilot"', 'James Burrows', 'Ed Yeager', '6.84', 'September24,2008', 101.0]
SQL:

assistant: SELECT MIN("Production code") FROM "Table" WHERE "Viewers" = '6.66';