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_name_71 (silver INTEGER, total VARCHAR, gold VARCHAR, nation VARCHAR)

### Question ###
Which Silver has a Gold of 2, and a Nation of puerto rico, and a Total smaller than 12?

### Accurate SQL ###

SELECT SUM(silver) FROM table_name_71 WHERE gold = 2 AND nation = "puerto rico" AND total < 12