user: Question: What is the highest channel number?
Columns: ['City', 'State or Territory', 'Station call sign', 'Network', 'Channel number', 'Programs Aired']
Types: ['text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Chicago', 'Illinois', 'WBBM-TV', 'CBS', 2.0, 'Juke Box Jury Sheriff of Cochise']
SQL:

assistant: SELECT MAX("Channel number") FROM "Table";