Note=int(input("notunuzu giriniz:"))
if (Note>=90):
    print("AA")
elif (Note>=85):
    print("BA")
elif (Note>=80):
    print("BB")
elif (Note>=75):
    print("CB")
elif (Note>=65):
    print("DC")
elif (Note>=55):
    print("CC")
else: 
    print("FF kaldınız")