user: Question: Name the most stage for Alejandro Valverde and Astana Greg Henderson
Columns: ['Stage', 'Winner', 'General Classification', 'Mountains Classification', 'Sprint Classification', 'Team Classification']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Thor Hushovd', 'Thor Hushovd', 'no award', 'no award', 'Cervélo TestTeam']
SQL:

assistant: SELECT MAX("Stage") FROM "Table" WHERE "General Classification" = 'Alejandro Valverde' AND "Team Classification" = 'Astana' AND "Winner" = 'Greg Henderson';