let message = readLine()!
let check1 = "hi"
let check2 = "hihi"
let check3 = "hihihi"
let check4 = "hihihihi"
let check5 = "hihihihihi"
if message == check1 || message == check2 || message == check3 || message == check4 || message == check5{
  print("Yes")
}else{
  print("No")
}
