module Main where

data Hello = NULL
           | H
           | E
           | L1
           | L2

sample = "ahhellllloou"

yoba [] = False
yoba xs = yoba' NULL xs

yoba' _ [] = False
yoba' NULL (x:xs) | x == 'h'  = yoba' H xs
                  | otherwise = yoba' NULL xs
yoba' H (x:xs) | x == 'e'  = yoba' E xs
               | otherwise = yoba' H xs
yoba' E (x:xs) | x == 'l'  = yoba' L1 xs
               | otherwise = yoba' E xs
yoba' L1 (x:xs) | x == 'l'  = yoba' L2 xs
                | otherwise = yoba' L1 xs
yoba' L2 (x:xs) | x == 'o' = True
                | otherwise = yoba' L2 xs

main :: IO ()
main = do str <- getLine
          if (yoba str)
            then putStrLn "YES"
            else putStrLn "NO"