human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Stage, Winner, General Classification, Youth Classification, Mountains Classification, Sprint Classification, Most Courageous, Team Classification
###Question: When Mark Cavendish wins sprint classification and Maarten Tjallingii wins most courageous, who wins youth classification?
gpt
SELECT Youth Classification FROM table WHERE Sprint Classification = Mark Cavendish AND Most Courageous = Maarten Tjallingii