You do not count your days in 2017 because that's the year when you still held the F-1 visa. It is considered as an exempt year (not counting days)
Therefore, you will add all days in 2019 plus 1/3 of the days in 2018 for your calculation.
@Le_nene
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
