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_50 ( fa_cup INTEGER, total VARCHAR, fa_trophy VARCHAR, club VARCHAR )

### Question ###
What is the sum of FA cups of club Stalybridge Celtic, which has more than 0 FA trophies and a total less than 20?

### Accurate SQL ###

SELECT SUM(fa_cup) FROM table_name_50 WHERE fa_trophy > 0 AND club = "stalybridge celtic" AND total < 20