Hello. Instructor Kim Young-han. I was so happy that you commented on my course review on August 2nd. I left my email address in the comment on August 2nd, but it seems like you didn't see it because it was a long time ago, so I'm leaving my email address again as a course review with today's date. I apologize again for the email sending error that occurred due to my mistake. My email address is jiyoung.kim@tysystems.com. I hope that the instructor's belief in knowledge sharing can be carried out through books as well, and I will wait for your email. Have a good weekend, and always take care of your health in the heat wave that continues day after day. Thank you. From Kim Ji-young (Vice President) of Dongyang Future Lab Publishing