i = 0
while i < 4:
  marks = input("Enter your marks")
  print(marks)

  marksInt = int(marks)

  grade = " "

  if marksInt < 40:
    grade = "D"
  elif marksInt < 60:
    grade = "C"
  elif marksInt < 80:
    grade = "B"  
  else:
    grade = "A"

  print("Your Grade is")
  print(grade)
  i =i+1