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 review (u_id VARCHAR)
TABLE: CREATE TABLE useracct (u_id VARCHAR)

### Question ###
Find the number of users who did not write any review.

### Accurate SQL ###

SELECT COUNT(*) FROM useracct WHERE NOT u_id IN (SELECT u_id FROM review)