Usually, the concepts in the beginning become vague as you go back, but Kim Young-han's lecture was good because he continuously applied what he learned earlier in the latter part, so there was less confusion. It was easy to understand because he explained with good examples, and honestly, I think he teaches better than my professor. In the past, I had no idea where to start just by looking at a problem, but as I listened to the lecture, I started to understand the concepts well, so I was able to solve the problems smoothly and gained confidence! Now, even though I haven't learned everything, I look forward to exciting problems and solving them the most.