I see that we both had the same interpretation issue...

As far as sort -u goes, I didn't know if the OP is on Windows, Unix or other platform. There is supposed to be an undocumented sort switch on Win10: sort /UNIQ, but I didn't bother to test that. This can be done in another way in the new PowerShell, but I didn't worry about that either. I also circled back to "what the heck does unique mean?".