user: Question: What is the lowest first prize of the Mercedes Championships tournament in California?
Columns: ['Date', 'Tournament', 'Location', 'Winner', 'Score', '1st prize ( $ )']
Types: ['text', 'text', 'text', 'text', 'text', 'real']
Sample row: ['Jan 9', 'Mercedes Championships', 'California', 'Phil Mickelson (4)', '276 (–12)', 180000.0]
SQL:

assistant: SELECT MIN("1st prize ( $ )") FROM "Table" WHERE "Location" = 'California' AND "Tournament" = 'Mercedes Championships';