let () =
  let s = Scanf.scanf "%s\n" @@ fun s -> s in
  let len = String.length s in
  let ans = ref true in
  for i = 0 to len - 1 do
    if (i mod 2 = 0 && s.[i] = 'h') || (i mod 2 = 1 && s.[i] = 'i')
    then ans := !ans && true
    else ans := !ans && false
  done;
  Printf.printf "%s\n" (if !ans && len <> 1 then "Yes" else "No")