# GeekDad Puzzle of the Week: Corrosive Gecko Climbs a Fence

Oh, no! Corrosive Gecko is at the bottom of the fence where he can be munched by Chirp-Chirp the carnivorous robin! Your job is to guide Corrosive Gecko, shown below, from his current position to the top of the fence.

Of course, there are some rules:

1. Each turn, Corrosive Gecko must move exactly one leg or arm. You pick which.

2. He can grab either horizontal or vertical sections of fence, but never at the junctions.

3. Each turn, Corrosive Gecko slides his appendage along the fence wire exactly the distance of one side of a grid box. This means that if Corrosive Gecko is holding a vertical wire, he may move his appendage straight up to the next box’s vertical wire (1), or may move his appendage up and then right (2), or up and then left (3). If C.G. is holding a horizontal wire, he may only move right and up (4), or left and up (5).

4. Being a rather corrosive gecko, anything he touches disintegrates the instant his appendage leaves it. Once he uses a spot, our acidic friend may not use it again.

5. He is not one of those window-sticking stretchy geckos. At any given time, CG’s appendages must stay within four “moves” of every other appendage. If not, he is ripped apart and squirts gecko guts across the fence, dissolving the entire lattice in one pump of a dying gecko’s heart (you get the point).

6. No more than two appendages may be in a vertical or horizontal line at any given moment.

7. Once CG reaches one hand or foot to the top wire, he wins. (And you may not do anything sneaky like removing an appendage for a move, jumping, or other intuitively forbidden folderol.)

8. If anyone is able to create and submit an accurate animation of Corrosive Gecko’s path up the fence, I will enter your name thrice in Friday’s drawing for a \$50 ThinkGeek gift certificate. Otherwise, find some other creative way to demonstrate CG’s path up the fence. Mail your answer to GeekDad Puzzle Central by Friday afternoon for your chance at the \$50 in riches from ThinkGeek.

* This is not a difficult puzzle, but consider learning to move Corrosive Gecko, because I’m sorely tempted to stick him on a more challenging fence two Mondays from now.

Here, without further ado and in stunning illustrative detail, is Corrosive Gecko and his fence-climbing conundrum: