# Write your Python code here
class Student:
  def _init__(self, name, marks):
    self.name = name
    self.marks = marks
    self.grade =

  def calculateGrade (self):
   if self.marks <40:
     self.grade = "D"
 elif self.marks < 60:

  self.grade = "C"

  elif self.marks < 80:

  self.grade = "B"

  else:

  self.grade = "A"

  def displayGrade(self):

  print(self.grade)

  st1 = Student("St1", 10)

  st2 = Student("St2", 45)

  st1.calculateGrade()

  st1.displayGrade()

  st2.calculateGrade()

  st2.displayGrade()