How to accessibly make a fill-in-the-blank

In HTML, I would like to have something like this:

<p>A man, a ____, a canal, panama.</p>

I do not want the underline/underscores to actually be an actual text input box. What would be a good way to mark this up in HTML such that it would be accessible to say, a screen reader? And while it's not required, if it is possible to convey that the underline is four characters long, all the better.