user: Question: What is the earliest stage where mountains classifications was awarded to Peter Stetina? 
Columns: ['Stage', 'Winner', 'General Classification', 'Mountains Classification', 'Sprint Classification', 'Team Classification']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Paul Voss', 'Paul Voss', 'no award', 'no award', 'Team RadioShack']
SQL:

assistant: SELECT MIN("Stage") FROM "Table" WHERE "Mountains Classification" = 'Peter Stetina';