user: Question: What episode number originally aired on November 21, 1993?
Columns: ['Overall Episode #', 'Original airdate', 'Iron Chef', 'Challenger', 'Challenger Specialty', 'Theme Ingredient', 'Winner']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'October 10, 1993', 'Yutaka Ishinabe', 'Takeshi Maruyama (丸山\u3000剛)', 'Chinese ( Cantonese )', 'Salmon', 'Yutaka Ishinabe']
SQL:

assistant: SELECT "Overall Episode #" FROM "Table" WHERE "Original airdate" = 'November 21, 1993';