A manager wants to determine the number of containers to use for incoming parts for a kanban system to be installed next month. The process will have a usage rate of $73$ pieces per hour. Because the process is new, the manager has assigned an inefficiency factor of $\mathrm{.}18.$ Each container holds $43$ pieces and it takes an average of $60$ minutes to complete a cycle. a$-1.$ How many containers should be used? $($Round up your answer to the next whole number.$)$ Number of containers: