user: Question: Who wrote episode number 81 in the series?
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: [63.0, 1.0, '"The Unsterile Cuckoo"', 'Rob Thompson', 'David E. Kelley', 'November2,1989', '7D01']
SQL:

assistant: SELECT "Written by" FROM "Table" WHERE "No. in series" = 81.0;