question: When Mark Cavendish wins sprint classification and Maarten Tjallingii wins most courageous, who wins youth classification?
answer: SELECT youth_classification FROM table_25055040_22 WHERE sprint_classification = "Mark Cavendish" AND most_courageous = "Maarten Tjallingii"
context: CREATE TABLE table_25055040_22 (youth_classification VARCHAR, sprint_classification VARCHAR, most_courageous VARCHAR)