CREATE TABLE store (store_id VARCHAR(255), store_name VARCHAR(255)); CREATE TABLE district (headquartered_city VARCHAR(255), district_id VARCHAR(255)); CREATE TABLE store_district (store_id VARCHAR(255), district_id VARCHAR(255))
Which city is the headquarter of the store named "Blackville" in?
    
SQL: SELECT t3.headquartered_city FROM store AS t1 JOIN store_district AS t2 ON t1.store_id = t2.store_id JOIN district AS t3 ON t2.district_id = t3.district_id WHERE t1.store_name = "Blackville"