package 
    statement as the first statement in the source file that contains the 
type (class, interface, enumeration, or annotation type).
To use a public type that's in a different package, you have three choices: (1) use the fully qualified name of the type, (2) import the type, or (3) import the entire package of which the type is a member.
The path names for a package's source and class files mirror the name of the package.
You might have to set your CLASSPATH so that the compiler and 
the JVM can find the .class files for your types.