user: Question: Which stage has a Winner of Lucien Van Impe?
Columns: ['Stage', 'Winner', 'General classification', 'Points classification', 'Trofeo Fast Team']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['P', 'Stage Cancelled', 'not awarded', 'not awarded', 'not awarded']
SQL:

assistant: SELECT "Stage" FROM "Table" WHERE "Winner" = 'Lucien Van Impe';