user: Question: Name the least number for production code for 3ABC21
Columns: ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: [46.0, 1.0, '"The Innocents"', 'Thomas J. Wright', 'Michael Duggan', 'October2,1998', '3ABC01']
SQL:

assistant: SELECT MIN("No. in series") FROM "Table" WHERE "Production code" = '3ABC21';