First, you must spread a thick layer of peanut butter onto the white part of a slice of bread. You can only spread the peanut butter on the white part, and the white part only. You may only spread peanut butter on one side. Spreading peanut butter on both sides will provide an inferior sandwich. Next, you must spread a thick layer of jelly onto the white part of a slice of bread. You can only spread the jelly on the white part, and the white part only. You may only spread jelly on one side. Spreading jelly on both sides will provide an inferior sandwich. You cannot spread jelly onto the same slice of bread onto which you have spread peanut butter.