question: What is the stage of Fabiano Fontanelli, who had a Trofeo Fast Team of Gewiss Playbus and a point classification of Fabrizio Guidi?
answer: SELECT stage FROM table_name_13 WHERE trofeo_fast_team = "gewiss playbus" AND points_classification = "fabrizio guidi" AND winner = "fabiano fontanelli"
context: CREATE TABLE table_name_13 (stage VARCHAR, winner VARCHAR, trofeo_fast_team VARCHAR, points_classification VARCHAR)