4. Consider the following dataset, which consists of a set of records with the format: (station name, month, day of the month, number of bikes rented that day) The dataset we are going to use is the following: (A, 2, 1, 70), (A, 2, 2, 80), (B, 1, 30, 30), (B, 1, 31, 40), (B, 2, 1, 50), (C, 2, 1, 70). Write down the Map and Reduce data flow steps/diagram to solve the following problems where you should randomly split the input data into two equal parts. (e) For each station and a month outputs the number of bikes rented (in total that month). [5 marks]