#找茬

  #找茬[役]

#!/usr/bin/env python
# -*- coding: utf-8 -*-
def char_diff(text):
  text=text.replace('\n','').replace('\r','')
  try:
    text=text.decode('gb18030','ignore')
  except:
    try:
      text=text.decode('utf-8','ignore')
    except:
      pass
  d={}
  for x in text:
    d[x]=d.get(x,0)+1
  lll= d.items()
  lll.sort(key = lambda x: x[1])
  return lll[0][0]
if __name__ == '__main__':
  while 1:
    text = raw_input("> ").decode('gb18030')
    #print type(text)
    if text in ['q','e','exit','quit','bye',u'退出']:
      print 'Bye!'
      break
    print u'#找茬[%s] ' % char_diff(text)