Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_28538368_2 ( mountains_classification VARCHAR, winner VARCHAR, general_classification VARCHAR, points_classification VARCHAR )

### Question ###
When Alberto Contador Kanstantsin Sivtsov was the general classification and Alessandro Petacchi was the points classification at the same time while Mark Cavendish is the winner, who was the mountain classification?

### Accurate SQL ###

SELECT mountains_classification FROM table_28538368_2 WHERE general_classification = "Alberto Contador Kanstantsin Sivtsov" AND points_classification = "Alessandro Petacchi" AND winner = "Mark Cavendish"