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_13346 ( "Class to 1928" text, "Class from 1928" text, "Seats" text, "Quantity" real, "Year(s) of Manufacture" text )

### Question ###
What's the sum of Quantity for the Class of 1928 of CI-30?

### Accurate SQL ###

SELECT SUM("Quantity") FROM table_13346 WHERE "Class from 1928" = 'ci-30'