import Control.Applicative
import Data.Bool (bool)

main :: IO ()
main = solve <$> getLine >>= putStrLn

solve :: String -> String
solve s = bool "No" "Yes" $ f s
  where
    f (x:y:ys)
      | x == 'h' && y == 'i' = f ys
      | otherwise = False
    f [_] = False
    f [] = True
