Who was the aggressive rider when the sprint classification was  andré greipel and mountains classification was timothy roe?
CREATE TABLE "classification_leadership" (
  "stage" real,
  "winner" text,
  "general_classification" text,
  "mountains_classification" text,
  "sprint_classification" text,
  "young_rider_classification" text,
  "team_classification" text,
  "aggressive_rider" text
);
SELECT "aggressive_rider" FROM "classification_leadership" WHERE "sprint_classification"='André Greipel' AND "mountains_classification"='Timothy Roe';