First of all,
You have not created any instance of class A yet is the main reason and after all, you have made your default constructor as Private so it cant be accessible is different class that's why your code for count increment in the private default constructor would not work at all. Each and every time after creating your instance in this code will get count to be Zero as a result.
MCSA 2003 | Preparing For OCPJP/SCJP6
subject: I am getting output as 0 but it must be 5 as i think