output_description: If S is a Hitachi string, print `Yes`; otherwise, print `No`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
attempt: hi = input()
  print("Yes" if set(hi[0::2]) == {"h"} and set(hi[1::2]) == {"i"} else "No")
  
problem_description: Statement
  
  A Hitachi string is a concatenation of one or more copies of the string `hi`.
  
  For example, `hi` and `hihi` are Hitachi strings, while `ha` and `hii` are
  not.
  
  Given a string S, determine whether S is a Hitachi string.
samples: [{"input": "hihi", "output": "Yes\n    \n\n`hihi` is the concatenation of two copies of `hi`, so it is a Hitachi string.\n\n* * *"}, {"input": "hi", "output": "Yes\n    \n\n* * *"}, {"input": "ha", "output": "No"}]