output_description: If it is possible to change S into `AKIHABARA`, print `YES`; otherwise, print
  `NO`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
attempt: #!/usr/bin/env python
  import re
  
  s = input()
  STR = 'AKIHABARA'
  if len(s) > len(STR):
      print('NO')
      exit()
  
  regex = re.compile('A?KIHA?BA?RA?')
  mo = regex.search(s)
  if mo == None:
      print('NO')
  else:
      print('YES')
  ~                 
problem_description: Statement
  
  You are given a string S.
  
  Takahashi can insert the character `A` at any position in this string any
  number of times.
  
  Can he change S into `AKIHABARA`?
samples: [{"input": "KIHBR", "output": "YES\n    \n\nInsert one `A` at each of the four positions: the beginning, immediately after\n`H`, immediately after `B` and the end.\n\n* * *"}, {"input": "AKIBAHARA", "output": "NO\n    \n\nThe correct spell is `AKIHABARA`.\n\n* * *"}, {"input": "AAKIAHBAARA", "output": "NO"}]