This is a simulation of the Chinses Wall security policy, as seen in original paper of Brewer and Nash. The program will ask for a description file. If the description file has errors, the program will output an error message and exit. Otherwise, it will prompt the user for access requests. Each request consists of a subject, an object, and whether the request is read or write. If the request is in error, like for example a non existing object, an error message is output. If it’s a valid request, the program will either grant or deny the request. If the access is granted, the program should update its data structures accordingly and prompts for another access request.