user: Question: which group stage was there 0 play-offs and 12 clubs played in it
Columns: ['Pos', 'Member Association', 'Points (total 500)', 'Clubs', 'Group stage', 'Play-off', 'AFC Cup']
Types: ['real', 'text', 'real', 'real', 'real', 'real', 'real']
Sample row: [4.0, 'Saudi Arabia', 365.0, 12.0, 4.0, 0.0, 0.0]
SQL:

assistant: SELECT "Group stage" FROM "Table" WHERE "Play-off" = 0.0 AND "Clubs" = 12.0;