★ Anyone can buy immediately if you check the notes at the bottom. I am selling this because I have finished reading it. Rather than solutions, the book is about the reasons why explanations are not understood. #No price negotiations -------------------- 【Please note in advance】 ★ If there is a description of "No price negotiations," I cannot do so. Please feel free to consult with me about price reductions in the comments. ★ Items sold as a set may be listed separately. If purchases overlap due to a time difference, the person who pressed the purchase button first will be given priority. ★ The shipping method may be changed later depending on the packaging situation. ★ Recycled cardboard may be used for packaging materials. ★ To keep costs low, items may be folded for shipping. (Mainly items that won't wrinkle will be folded) If you are resistant to wrinkles, please contact me after pressing the purchase button. ※ I cannot guarantee that there will be absolutely no wrinkles. ★ I try to reply within 3 days, but it may be delayed due to work or personal matters.