user: Question: What Distance had a Race Leader in km (mi)?
Columns: ['Date', 'Course', 'Distance', 'Winner', 'Race Leader']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['16 May', 'Milan to Turin', 'km (mi)', 'Giuseppe Olmo ( ITA )', 'Giuseppe Olmo ( ITA )']
SQL:

assistant: SELECT "Distance" FROM "Table" WHERE "Race Leader" = 'km (mi)';