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_28230 ( "Stage" real, "Winner" text, "General classification" text, "Points classification" text, "Mountains classification" text, "Young rider classification" text, "Team classification" text, "Combativity award" text )

### Question ###
How many mountains classifications when Rui Costa is the winner?

### Accurate SQL ###

SELECT COUNT("Mountains classification") FROM table_28230 WHERE "Winner" = 'Rui Costa'