This was the hardest challange in my opinion. I could not figure out how to do it until it was about a week till it was over and I 
had loads of homework to boot. That aside, onto the robot. It uses repelling magnets to lift the little pieces that the human presses down
when in neutral, all pieces rest the same so when one motor goes forward, one is raised while the other drops (it is up to the 
human to press the raised pieces in the right order) and when that motor goes in reverse, the opposite occurs; the previously 
lowered one now rises while the previously raised one drops.Touch sensors allow for the robot to rest the magnets in a neutral
posision. The light sensor tells the RCX what order the tiles are being pressed down. Not much else about this robot except the
huge program that took me 3 hours to write. I would also like to say that sometimes the tiles don't raise when they are supposed 
to which I belive has to do with the alignment of the bricks that make up the chambers or the bricks that the buttons are made out of.