"""

Starting in the top left corner of a 2x2 grid, and only being able to move to the right and down,
there are exactly 6 routes to the bottom right corner.
 _ _        _ _   _     _
|_|_|  =>      |   |_    |   |     |_     |_ _
|_|_|          |     |   |_  |_ _    |_       |


How many such routes are there through a 20x20 grid?


"""

GRID_SIZE = [20, 20]