Suppose you are a Rock Climber, standing at the
Mountain's foot. The Mountain consists of the rocks colored into four
different colors - blue, green, red and yellow - as shown in the
You object is to get to the Mountain's top, always climbing from one
rock to another adjacent rock, but never jumping over the rocks. As
you climb to the top your route must contain a definite consecution of
four colors constantly repeating. For example, yellow-green-blue-red-,
and then again yellow-green-blue-red-, and so on.
How quickly can you get to the top?