"Eighteen, nineteen, twenty."
Hello, unfortunately they are not accepted for all questions and that's why I was asking this question. Many thanks.
There's no easy way (that I know of) to make changes for all sentences, of the kind "wherever δεκαεννιά is accepted, make sure that δεκαεννέα is accepted as well", so best to report individual sentences where one is not accepted.
Also, note the position of the accents -- it's not on δέκα in those compound words since that would be too far back.