output_description: If there is a pair of stations that will be connected by a bus service, print
  `Yes`; otherwise, print `No`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
attempt: L = list(input())
  print("No" if L.count("A") == 0 and L.count("B") == 0 else "Yes")
  
problem_description: Statement
  
  In AtCoder City, there are three stations numbered 1, 2, and 3.
  
  Each of these stations is operated by one of the two railway companies, A and
  B. A string S of length 3 represents which company operates each station. If
  S_i is `A`, Company A operates Station i; if S_i is `B`, Company B operates
  Station i.
  
  To improve the transportation condition, for each pair of a station operated
  by Company A and one operated by Company B, there will be a bus service
  connecting them.
  
  Determine if there is a pair of stations that will be connected by a bus
  service.
samples: [{"input": "ABA", "output": "Yes\n    \n\nCompany A operates Station 1 and 3, while Company B operates Station 2.\n\nThere will be a bus service between Station 1 and 2, and between Station 2 and\n3, so print `Yes`.\n\n* * *"}, {"input": "BBA", "output": "Yes\n    \n\nCompany B operates Station 1 and 2, while Company A operates Station 3.\n\nThere will be a bus service between Station 1 and 3, and between Station 2 and\n3, so print `Yes`.\n\n* * *"}, {"input": "BBB", "output": "No\n    \n\nCompany B operates all the stations. Thus, there will be no bus service, so\nprint `No`."}]