user: Question: Tell me the sum of the grid with Alfa Romeo and Toulo de Graffenried
Columns: ['Driver', 'Constructor', 'Laps', 'Time/retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Alberto Ascari', 'Ferrari', 80.0, '2:42:39.3', 3.0]
SQL:

assistant: SELECT SUM("Grid") FROM "Table" WHERE "Constructor" = 'Alfa Romeo' AND "Driver" = 'Toulo de Graffenried';