>>42494918
>>42498075
Oh, right, it was probably good to mention chapter splits; for some reason I read 20 as an odd number. Pay attention to chapter titles! 2/3 of the fic is titled 'Lost', and the prologue chapters are included in the count.
Week 1: Chapters 1-11, inclusive of ch.11 (fourth 'Lost' in a row).
Week 2: Chapters 12-22, ending with the last 'Lost' in its batch.
Week 3: The rest, starting with Chapter 23, 'The Adventure'.