# Write your Python code here

for i in range(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)