# -*- coding: utf-8 -*-
"""
Created on Thu Jun 08 17:27:37 2017
@author: Administrator
"""

'''
The goal of this program is to find the level of input score
'''
score = int(raw_input("Please input the score"))
if (90 < score <= 100):
  print "A"
elif (70 <= score <= 89):
  print "B"
elif (60 <= score  <= 69):
  print "C"    
elif (0 < score  <= 59):
  print "D"
else :
  print "others Invalid score" 
3dafd145f7ea4d5a6e9bc6f51da733de45516ce1
# -*- coding: utf-8 -*-
"""
Created on Thu Jun 08 17:27:37 2017
@author: Administrator
"""

'''
The goal of this program is to find the level of input score
'''
score = int(raw_input("Please input the score"))
if (90 < score <= 100):
  print "A"
elif (70 <= score <= 89):
  print "B"
elif (60 <= score  <= 69):
  print "C"    
elif (0 < score  <= 59):
  print "D"
else :
  print "others Invalid score" 