Pumpkin team: We would like first to congratulate you, Banana team, for your first great written article! The first two parts about the business and data understanding are great introduction of the goal of the Monthly challenge and about the main aspects of the issue which we are dealing with – the air pollution in the capital of Bulgaria. We appreciate the simple and clear operations that you have used in your code because it is easy for the others to follow your steps and logic as well as to help those who do not fully understand the functions used in the code. It is obvious that you have given much effort and managed to apply a big variety of R commands. We do not have any remarks for improvements at this stage but only would like to ask about one of the filters you intend to apply – why do you want to filter to the stations which are missing in 2018 and why you checked whether there are some missing both in 2017 and 2018? Our approach, for example, is to look at the latest data (excluding the stations which do not appear in 2018) because in order to make a forecast we want to use the latest information. Maybe you meant the same but we just want to double-check. 🙂