This is a set of two books, 2023 and 2020. They are not for sale separately. *Please refrain from price negotiations. (We will decline even if you leave a comment.)* **[2023]** The seller personally checked the book and confirmed that there are no highlighter marks, underlines, or writing. (Please forgive any oversight.) There are no signs of use in exercises, and the book is in very clean condition, like new. **[2020]** There is a slight fold (1cm vertically, 3cm horizontally) at the bottom of the cover. There was some writing in pencil on some pages, but the seller has erased it all. We believe this will not affect the exercises.