#!/usr/bin/python

x = int(raw_input('please input:'))

if x >= 90:

    if x >= 95:

        print 'a+'

    else:

        print 'a'

elif x >= 80:

    if x >= 85:

        print 'b+'

    else:

        print 'b'

elif x >= 70:

    if x >= 75:

        print 'c+'

    else:

        print 'c'

else:

    if x >= 60:

        print 'd+'

    else:

        print 'bad'

#!/usr/bin/python

x = int(raw_input('please input x:'))

y = int(raw_input('please input y:'))

if x >= 90 and y >= 90:

    print 'a'

elif x >= 80 or y >= 80:

    print 'b'

elif not x < 60 and (not y < 60):

    print 'c'

else:

    print 'bad'

#!/usr/bin/python

s = "hello python"

for x in s:

    print x

for index in range(len(s)):

    print s[index]

#!/usr/bin/python

dic = {'a':1,'b':2,'c':3}

for x in dic:

    print x,dic[x]

for k,v in dic.items():

    print k,v

#!/usr/bin/python

import time

for x in range(10):

    print x

    time.sleep(1)

else:

    print 'end'

#!/usr/bin/python

for x in range(10):

    print x

    if x == 6:

        break

else:

    print 'end'

#!/usr/bin/python

for x in range(10):

    print x

    if x == 2:

        print 'hello',x

        continue

    if x == 4:

        pass

    if x == 5:

        exit()

    if x == 6:

        break

    print '*'*10

else:

    print 'end'

#!/usr/bin/python

x = 'hello'

while x != "q":

    print x

    x = raw_input('please input something,q for quit:')

    if not x:

        break

else:

    print 'ending'