Pick A Shell

Remember the shell game you used to play in the back alley with the people you weren't supposed to hang out with? Well, Uberwares has taken it out of the alley, given it a makeover, and is now offering to you free of charge. No ads either! Sweet! INSTRUCTIONSIt really couldn't be simpler. Find a pearl...get a point. Don't find a pearl...lose a point! Try to keep your score out of the negative range. There are only 3 shells. How hard could it be?!!!!!!