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 manufacturers ( revenue INTEGER, Headquarter VARCHAR )

### Question ###
What is the total revenue of all companies whose main office is at Tokyo or Taiwan?

### Accurate SQL ###

SELECT SUM(revenue) FROM manufacturers WHERE Headquarter = 'Tokyo' OR Headquarter = 'Taiwan'