We are sorry for not being clear on the answer to the last review. This paper tried to present a concept for the smart city structure to cope with major situations such as COVID-19. Therefore, it was not possible to present a specific method of adding or removing a smart city system. Currently, smart city services in Korea are trying to implement a structure that adds and deletes when necessary, as in this paper (Reference #73). However, we apologize for not being able to give you a clear answer on this question. After observing the process of implementing the system, we will present a specific method in the thesis we plan to proceed later.
Finally, and this is my biggest remaining concern, the authors have not responded to my comment regarding the lack of explanations on how the flexible adding and removal of the proposed services would be achieved. This is still unclear to me in the paper. This is a very important point, since it changes what is the contribution of the paper. The current contribution seems to be the proposal of new services to handle the COVID situation, or similar situations in the future. However, I am lacking the contribution on the more general issue of integrating and removing services in an existing smart city infrastructure. In other terms, what can we use from the authors' paper to achieve a more flexible smart city service structure?