user: Question: What is the highest episode number in which Jamie Oliver guest-hosted?
Columns: ['Episode Number', 'Air Date', 'Guest Host', 'Musical Guest (Song performed)', 'Who knows the most about the guest host? panelists']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1.0, '6 January 2006', 'Billie Piper', 'Texas ( Sleep )', 'Jade Goody and Kenzie']
SQL:

assistant: SELECT MAX("Episode Number") FROM "Table" WHERE "Guest Host" = 'Jamie Oliver';