A local hospital wants to set up a kanban system to manage its supply of blood with the regional blood bank. The regional blood bank delivers blood to the hospital each day with 6 days order lead time. Internally, the hospital purchasing group places orders for blood each day at 5 P.M. Blood is measured by the pint and is shipped in containers that contain 70 pints. For a particular blood type, the hospital uses an average of 360 pints per day. Due to the critical nature of a blood shortage, the hospital wants to carry a safety stock of 20 percent of daily demand. How many kanban card sets should the hospital prepare?