user: Question: What is the smallest round to have a record of 4-0?
Columns: ['Result', 'Record', 'Opponent', 'Method', 'Event', 'Round', 'Location']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Win', '6-0', 'Phillip Hellesoe', 'TKO', 'Sky City Convention Centre', 2.0, 'Auckland, New Zealand']
SQL:

assistant: SELECT MIN("Round") FROM "Table" WHERE "Record" = '4-0';