user: Question: what is the surface when the winner and score is Gustavo Kuerten 6-4, 7-5, 7-6(6)?
Columns: ['Tournament', 'Surface', 'Week', 'Winner and score', 'Finalist', 'Semifinalists']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Indian Wells', 'Hard', 'March 8', 'Mark Philippoussis 5-7, 6-4, 6-4, 4-6, 6-2', 'Carlos Moyá', 'Chris Woodruff Gustavo Kuerten']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Winner and score" = 'Gustavo Kuerten 6-4, 7-5, 7-6(6)';