Given all letters in the english alphabet organized alphabetically in a 2d array find the shortest path to spell any word by navigating the 2d array with a combination of up, down, left and right movements.

For example, a 3 x 9 "keyboard" would look like this:

 a b c d e f g h i
 j k l m n o p q r
 s t u v w x y z

In this case, the word zebra is comprised of the following indices:

[(2, 7), (0, 4), (0, 1), (1, 8), (0, 0)]

The shortest path for this word, starting at the letter a is:

[(-1, -2), (1, -3), (0, -3), (1, -2), (-1, 1)]

where negative represents up or left and positive represents down or right.

So, (-1, -2) means move 1 row up and 2 columns to the left or:

up, left, left

which moves the cursor from the letter a at (0, 0) to the letter z at (2, 7).