Get an Unlimited Supply of Command Blocks from 1 Command and Sign! by evil_creeper

Hello! this is my first Command! I made a Custom Sign where you can get 20 free Command Blocks without putting in the Command in the Chat! [I highly Recommand Using this on your own Multiplayer Server or on Singleplayer!] Comment Below if the Command doesn't Work! [Must Look what Version it works for! 1.8.9]