Thank you. I will take time to supplement the content. I have already started the improvement work, and I will gradually re-upload the lectures (it may take several months to re-upload everything), so I would appreciate it if you could check them out again.

I've supplemented lesson 1-1 for now. Please compare the previous lesson 1-1 with the revised lesson 1-1 and let me know if it would be good to explain in more detail in the same format as the revised version. I would appreciate it.