The conversation between human and AI assistant.
[|Human|] Who are the main cast of It's Always Sunny in Philadelphia?
[|AI|] The main cast of the TV show It's Always Sunny in Philadelphia are Charlie Day, Rob McElhenney, Glenn Howerton, Kaitlin Olson, Danny DeVito, and Mary Elizabeth Ellis.
[|Human|] 
Who are the main cast of It's Always Sunny in Philadelphia?