Working in your CentOS Linux machine, find out the steps to add users to the system (regular user accounts) without using any tool (like useradd, or a GUI, or anything alike). You must add them manually (understand this as modifying the right files, creating the appropriate directories with appropriate files in them, and setting the appropriate ownership and permissions on the directories and files). The user must be able to log in using a password (which could be set on the first log in attempt) into the system to their home directory. The users home directory should also include the following directories: Documents, Desktop, Downloads, and Public.