user: Question: How many different constructors had Paul Thiel as a winning driver?
Columns: ['Race Name', 'Circuit', 'Date', 'Winning driver', 'Constructor', 'Report']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['IV Gran Premio di Siracusa', 'Syracuse', '11 April', 'Nino Farina', 'Ferrari', 'Report']
SQL:

assistant: SELECT COUNT("Constructor") FROM "Table" WHERE "Winning driver" = 'Paul Thiel';