user: Question: What is the smallest grid for Ayrton Senna?
Columns: ['Driver', 'Constructor', 'Laps', 'Time/Retired', 'Grid']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Niki Lauda', 'McLaren - TAG', 70.0, '1:32:29.263', 10.0]
SQL:

assistant: SELECT MIN("Grid") FROM "Table" WHERE "Driver" = 'Ayrton Senna';