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.
S = input()

if S in 'hi':
  print('Yes')
else:
  print('No')
def main():
  S = input()
  lst = []
  for i in range(1, 100):
    lst.append('hi' * i)

  for it in lst:
    if S == it:
      print('Yes')
      return

  print('No')
  
if __name__ == '__main__':
  main()