I suddenly found myself preparing for the civil service exam, and since I'm weak at memorization, I was initially studying inefficiently by focusing on problem-solving. Then I started organizing concepts with Python and the content began to be understood much more intuitively, especially difficult concepts like the characteristics of stream ciphers became easy to memorize once I coded them directly. I really want to recommend this to those who, like me, switched from development to civil service exams. I'm truly grateful that I can listen to such beneficial lectures for free. This was the lecture that helped me the most while preparing for the civil service exam.