class Student                                      
    {
         public int stu_no = 10011;             //ѧ
         public String stu_name;               //ѧ
         public String specialty;               //רҵ                           
         void printStu_no ()                  
         {
            System.out.println ("stu_no of Student is " + stu_no);     
         }
     }//end Student
     class GraduateStudent extends Student
     {
         public int stu_no = 20011;                    
         public String tutor;                          
         public String spec_direction;                  
         void printStu_no ()                  
         {
         super.printStu_no();                    //ø౻ǵķ
             System.out.println ("stu_no of GraduateStudent is" + this.stu_no); 
         }
         void printStu_no (int stu_no)                  
         {
             this.printStu_no();                 //ͬеķ
             System.out.println ("stu_no of GraduateStudent is" + stu_no); 
         }
         public static void main(String[] args)         
         {  
             GraduateStudent stu1 = new GraduateStudent();                     
             stu1.printStu_no(30011);            
         }
      }//end GraduateStudent
