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_200_33 ( id number, "district" text, "area size\n(km2)" text, "population" text, "density\nper km2" number )

### Question ###
what is the combined area size of the yamato flat inland plain and the yamato highland ?

### Accurate SQL ###

SELECT SUM("area size\n(km2)") FROM table_200_33 WHERE "district" IN ('yamato flat inland plain', 'yamato highland')