CREATE TABLE table_22713796_14 (stage INTEGER, winner VARCHAR(255), general_classification VARCHAR(255), team_classification VARCHAR(255))
Name the most stage for alejandro valverde and astana greg henderson
    
SQL: SELECT MAX(stage) FROM table_22713796_14 WHERE general_classification = "Alejandro Valverde" AND team_classification = "Astana" AND winner = "Greg Henderson"