Hi Professor Wise, I am concerning that in Ass2, are we allowed to creating temporary file? For example, I may join the 3 input files in to a new tsv file and clean it named cleaned.tsv, than use awk '{print}' to send to standard output. Also, I am not sure whether there is any required calculation accuracy in the project, and notice that the sample output accurate to three decimal places, so should we keep the accuracy during all calculation in the script? Thank you very much. Best regards. Zhiyang