user: Question: What is the highest numbred district that has Brian W. Thomas as an incumbent?
Columns: ['District', 'Incumbent', 'Party', 'Elected', 'Status', '2010 Candidates']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Jay Neal', 'Republican', '2004', 'Re-elected', 'Jay Neal (R) unopposed']
SQL:

assistant: SELECT MAX("District") FROM "Table" WHERE "Incumbent" = 'Brian W. Thomas';