open Printf
open Scanf

let solve s =
  let l = String.length s in
  let rec f i n =
    if i = n then "Yes"
    else if s.[i] = 'h' && s.[i+1] = 'i' then f (i + 2) n
    else "No" in
  if l mod 2 = 1 then "No"
  else f 0 l

let () =
  scanf "%s " solve |> printf "%s\n"
