"would have taken" vs "would had taken"

Hello,

Could you please suggest which of the following sentences is

correct? (To context is that there is a book I had not read in the

past because it was too big.)

1) It would have taken me a month to read this book.

2) It would had taken me a month to read this book.

I guess that the first variant is correct; if so, then is there a single

case where "would had {past participle}" must be used?

Thanks in advance.

--

Victor