Minecarft won't work it says it's modded?

Ok so I downloaded the mods and put it in the mods folder and it says the minecraft game is modes when I play it so I put them in the folder 1 by 1 and played the game I between each one to see if it works and it will only let me have 2 mods in without it crashing and saying its modded how do I fix it please help!