You put them all on a paper slips, chew them up, swallow, and whatever ones you poop out, are free!
You are obviously new to league they have a very long and complicated system on who they make free they have to take feedback from players, they have to figure out if the free champion rotation is 2 strong or 2 weak!
So you dont know what you are talking about and you need to learn the game just a little bit more before you come into the forums and start talking smack about Riot, because they are very busy trying to make this game the best it can be for people like you and me and everybody around the entire world who play LoL.
So learn the game and get a level 30 account then come talk to Riot about their pros and cons or their ups and down or even their flaws!!!!!