Hi,
I agree with whatever Ankit said.
Disclaimer

: Based on what-ever knowledge I possess, I am giving this answer.
Note: 1) You have placed the class 'A' inside the package 'AA'. So you can't access the class 'A' in Simple.java directly.
Either you have to import it from the package 'AA' or use the fully qualified class name as AA.A
2) Since the class 'A' is in the package 'AA', the folder which consists the AA package should be in the class path, i.e. nothing but 'com' which is the current working directory as per your post.
So actually you don't need the classpath
3) If you want to access a class from a different package in your class, you need to import it or use fully qualified name. I think you can't get the class using 'Classpath'.
As you know Classpath just tells the compiler to look in the path for the classes
With this said, there are two ways to get the output "Inside class A"
Solution 1: just import the class A
com>javac Sample.java
com>java Sample
Inside Class A
Solution 2: Use the fully qualified class name AA.A
com>javac Sample.java
com>java Sample
Inside Class A