hm he+em he+em
hm he em he em .
h a ɛ m WORD_BOUNDARY h ɛ WORD_BOUNDARY  ɛ m WORD_BOUNDARY h ɛ WORD_BOUNDARY  ɛ m WORD_BOUNDARY
h m WORD_BOUNDARY h e WORD_BOUNDARY e m WORD_BOUNDARY h e WORD_BOUNDARY e m WORD_BOUNDARY