class Student                                      //
       {        
           void printStuMeassage ()                           
           {
               System.out.println ("a student ");     
            }
       }//end Student
       class GraduateStudent extends Student                  //
       {         
          void printStuMeassage ()                          //
          {
              System.out.println ("a graduate student "); 
          }
          void printStuMeassage (String name)                  
          {
              System.out.println ("a graduate student : " + name); 
          }
         public static void main(String[] args)         
         {  
            Student s = new Student();                     
            s.printStuMeassage();           
            GraduateStudent g = new GraduateStudent();
            g.printStuMeassage(); 
            g.printStuMeassage("Tom");            
         }         
      }//end GraduateStudent
