user: Question: What is the smallest crowd size for an away team that scored 7.15 (57)?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['North Melbourne', '9.13 (67)', 'St Kilda', '15.13 (103)', 'Arden Street Oval', 17261.0, '7 May 1966']
SQL:

assistant: SELECT MIN("Crowd") FROM "Table" WHERE "Away team score" = '7.15 (57)';