The lecture content was not bad. However, I would understand if it were offline, but it was disappointing that they said during the lecture that the prepared lecture materials were wrong and that they should be corrected or that the contents should be checked again, because there was time to check them online, but it felt like they were not properly prepared. And I think it was difficult to concentrate on the lecture because they repeatedly used unnecessary words that were not necessary. However, I liked the fact that they tried to explain difficult terms easily and tried to convey the latest contents.