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_58163 ( "Platform" real, "Frequency (per hour)" real, "Destination" text, "Operator" text, "Line" text )

### Question ###
what is the platform when the frequency (per hour) is 4 and the destination is west croydon?

### Accurate SQL ###

SELECT SUM("Platform") FROM table_58163 WHERE "Frequency (per hour)" = '4' AND "Destination" = 'west croydon'