생각해 볼 문제

 

 

 

https://www.youtube.com/watch?v=kNZGmGaM3oE&ab_channel=%EB%B0%95%EC%A2%85%ED%9B%88%EC%9D%98%EC%A7%80%EC%8B%9D%ED%95%9C%EB%B0%A9