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: # 1st: Code Festival 2015 Qualifying B (0408)
  if False:
      N, M = map(int, input().split())
      A = [int(i) for i in input().split()]
      B = [int(i) for i in input().split()]
      A.sort()
      B.sort()
      ans = "YES"
      if N < M:
          ans = "NO"
      else:
          while B:
              a = A.pop()
              b = B.pop()
              if b > a:
                  ans = "NO"
                  break
      print(ans)
  
  # 2nd: CF2014QA-C
  if False:
      A, B = map(int, input().split())
  
      def uruu(n):
          ret = 0
          ret += n // 4
          ret -= n // 100
          ret += n // 400
          return ret
  
      print(uruu(B) - uruu(A - 1))
  
  # 3rd: Code Formula 2014 - C
  if False:
      S = input()
      stack = list(S[::-1])
      # print(stack)
      user = []
      s = stack.pop()
      while stack:
          # print(s)
          if s == "@":
              tmp = ""
              x = stack.pop()
              while not (x in ("@", " ")):
                  # print(x)
                  tmp += x
                  if not stack:
                      break
                  x = stack.pop()
              user.append(tmp)
              s = x
          else:
              s = stack.pop()
      user = list(set(user))
      user.sort()
      for u in user:
          if u:
              print(u)
  
  # 4th: Hitachi Programming Contest 2020 - A
  if True:
      S = input()
      hi = ["hi" * i for i in range(1, 10)]
      print("Yes" if S in hi 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"}]