object Main extends App {
  val in = scala.io.Source.stdin.getLines.toSeq
  val S = in(0)
  
  private def func():String ={
  if(S.size % 2 != 0) return "No"
  (0 until S.size).foreach{ i=>
    if((i%2 == 0 && S(i) != 'h') || (i%2 == 1 && S(i) != 'i' ) ) return "No"
  }
  return "Yes"
  }
  println(func())
}
