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_18898 ( "Title and Source" text, "Developer(s)/Publisher(s)" text, "JP -210-" text, "NA -350-" text, "PAL -295-" text, "Wii Points" text )

### Question ###
how many na -350- with title and source being bokumo sekai wo sukuitai: battle tournament

### Accurate SQL ###

SELECT COUNT("NA -350-") FROM table_18898 WHERE "Title and Source" = 'Bokumo Sekai wo Sukuitai: Battle Tournament'