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_22903426_1 ( scm_system VARCHAR, windows_builders VARCHAR )

### Question ###
Name the number of scm system for nant, visual studio

### Accurate SQL ###

SELECT COUNT(scm_system) FROM table_22903426_1 WHERE windows_builders = "NAnt, Visual Studio"