user: Question: Name the least series number for episode number being 78
Columns: ['Episode No. Episode No. refers to the episodes number in the overall series, whereas Series No. refers to the episodes number in this particular series.', 'Series No.', 'Episode', 'Director', 'Writer', 'Original airdate']
Types: ['real', 'real', 'text', 'text', 'text', 'text']
Sample row: [66.0, 1.0, '"Humpty Dumpty"', 'Jim Hill', 'Ginnie Hole', '6September1991']
SQL:

assistant: SELECT MIN("Series No.") FROM "Table" WHERE "Episode No. Episode No. refers to the episodes number in the overall series, whereas Series No. refers to the episodes number in this particular series." = 78.0;