Question: How many teams have a combination classification of Alejandro Valverde and a Points classification of Alessandro Petacchi?
Schema: create table table_15059783_1 (team_classification varchar, combination_classification varchar, points_classification varchar, PRIMARY KEY (team_classification))
SQL: select count(team_classification) from table_15059783_1 where combination_classification = "alejandro valverde" and points_classification = "alessandro petacchi"