A customer performs a full backup on the first Sunday of the month followed by a cumulative backup on the other Sundays. They also perform an incremental backup each day Monday through Saturday. Tapes are sent offsite for disaster recovery every morning at 10 a.m. The customer experiences a system crash on the Wednesday of the third week at 3 p.m., requiring a system recovery. How many days worth of tapes need to be retrieved to perform a recovery?