How to export all text from an INDESIGN file

This doubt has come to me today: "What if, for some special reason, I need just the text from an Indesign file? How to extract? Might I COPY and PASTE, one by one, the blocks of text to an editor like Word?"
For my happiness, I've found a way to save all the text in one file, in three simple steps.

1) Export the Indesign file as HTML.
2) Open it in Word or Libre Office Writer.
3) Save it as TXT. This third step will eliminate all eventual images. You must close it and open again to see this.

The disadvantage is that the text looses its formatting (fonts, sizes etc). But if the most important is to have the complete text in an unique file, this is a very fast solution.