please don't solve the question with excel or lingo.

A transport company requires the following number of drivers for its trucks during 24 h. Time Period Number Required 00-04 h 04-08 h 08-12 h 12-16 h 16-20 h 20-24 h 6 10 20 14 20 10 A driver may join for duty at midnight, 04, 08, 12, 16, and 20 h, and work for either 4 or 8 h long shift. To ensure smooth operation, at least half the drivers must be employed for 8 h shift in a 24 h cycle. Formu- late the problem to find the number of drivers start at the beginning of each time period for both 4 and 8 h shift by minimizing the total number of driver-hours to be employed