marks = float(input("Enter average marks of the student: "))

if (marks>=90):
  print("Grade : A")
elif (marks>=80):
  print("Grade : B")
elif (marks>=70):
  print("Grade : C")
elif (marks>=60):
  print("Grade : D")
elif (marks>=50):
  print("Grade : E")
else:
  print("Fail")
