You need to program call management for the complex shown in the figure below, consisting of two office and residential buildings and a residents-only car park.

The access-control devices positioned at each passage are shown in red.

Entrance D

CAR PARK

BLOCK C

Entrance C

Entrance B

BLOCK B

PORTER'S LODGE

Entrance A

Customer requests

All calls from any entrance must be directed to the porter (during the porter's working hours from 8:00 a.m. to 6:00 p.m.). The porter will forward calls to the relevant

internal receivers in the two buildings.

On the days/at the times when the porter is absent, calls must go directly to the intended recipient.