class student:
  def __init__(self,sid,sname,grade):
    self.sid = sid
    self.sname = sname
    self.grade = grade
    
  def dispaly(self):
    print(f"Student ID: {self.sid}, Name: {self.sname}, Grade: {self.grade}.")
    
class teacher:
  def __init__(self,teacher_id,name,subject):
    self.teacher_id = tid
    self.name = name
    self.subject = subject
  
  def dispaly(self):
    print(f"Teacher ID: {self.stid}, Name: {self.name}, Grade: {self.subject}.") 
    
class course:
  def __init__(self,ccode,cname,teacher,students=None):
    self.course_code = code
    self.course_name = cname
    self.teacher = teacher
    self.students = students if students is not None else []
    
    
  def add_student(self,student):
    self.students.append(student)
    
  def remove_student(self,student):
    self.students.remove(student)
    
  def display(self):
    return f"Course Code: {self.Course_code}, Course Name: {self.course.name}\n"\
           f"Teacher: {self.name}, subject = {self.techer.subject}\n"\
           f"students: {','.join([student.name for student in self.students])}"
           
students = []
teachers = []
courses = []

while True:
  print("1. Create Student\n2 create Teacher\n3 Add Student to Course\n4 Remove Student\n5 Add Course\n6 display\n7 Exit.")
  ch = int(input("Enter the choice:"))
  
  if ch == 1:
    sid = int(input("Enter the stuenent id: "))
    name = input("Enter the Name:")
    grade = int(input("Enter grade:"))
    s = student(sid,name,grade)
    students.append(s)
    
  elif ch == 2:
    tid = int(input("Enter Teacher id:"))
    name = input("Enter Teacher name:")
    subject = input("Enter subject:")
    t = teacher(tid,name,subject)
    teachers.append(t)
    
  elif ch == 3:
    code = input("Enter subject code:")
    student_id = int(input("Enter student id:"))
    student = next((student for student in students if student.student_id== student_id), None)
    if student:
      course = next((course for course in courses if course.course_code == code), None)
      if course:
        couse.add_student(student)
      else:
        print("Course not found.")
    else:
      print("Student not found.")
      
  elif ch == 4:
    code = input("Enter course code:")
    student_id = int(input("Enter student id:"))
    course = next((course for course in courses if course.course_code == code), None)
    if course:
      student = next((student for student in students if student.student_id== student_id), None)
      if student:
        course.remove_student(student)
      else:
        print("Student not found in the course")
    else:
      print("Course not Found.")
      
  elif ch == 5:
    code = input("Enter course code:")
    name = input("Enter the course name:")
    course_teacher_id = int(input("Enter teacher id for the course:"))
    teacher = next((teacher for teacher in teachers if teacher.teacher_id == course_teacher_id ), None)
    if teacher:
      couse = course(code,cname,teacher)
      course.append(course)
    else:
      print("Teacher not found.")
      
  elif ch == 6:
    for course in courses:
      print(course.display())
      
  elif ch == 7:
    break