user: Question: Who was the challenger when Guillaume Brahimi was the iron chef?
Columns: ['Episode', 'Airdate', 'Iron Chef', 'Challenger', 'Theme Ingredient', 'Winner']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '19 October 2010', 'Neil Perry', 'Matt Stone', 'Coconut', 'Neil Perry']
SQL:

assistant: SELECT "Challenger" FROM "Table" WHERE "Iron Chef" = 'Guillaume Brahimi';