There is a question about cs, why is the access list overwritten?

Question

Cisco Packet Tracer

The corporate network consists of four networks:
network 1 - 11.0.0.0/8;
network 2 - 12.0.0.0/8;
network 3 - 13.0.0.0/8;
network 4 - 14.0.0.0/8.
Each network has a Web site installed on the server.
Assignment:
Computer comp2 can only access computers on its network and comp4.
Computer comp4 can only access computers on its network and comp2.
Computer comp8 can only access computers on its network and comp6.
Computer comp6 can only access computers on its network and comp8.
Computers comp1, comp3, comp5 and comp7 should open all sites on servers S1, S2, S3 and S4.