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_35 ( example_code__huc_ INTEGER, level VARCHAR, example_name VARCHAR, digits VARCHAR )

### Question ###
What is the mean huc example code when the example name's lower snake, there are 6 digits, and less than 3 levels?

### Accurate SQL ###

SELECT AVG(example_code__huc_) FROM table_name_35 WHERE example_name = "lower snake" AND digits = 6 AND level < 3