Place two 4x1
vertical stack of tiles and three 3x1
vertical stack of tiles on the grid. The order in which you place the tiles is random (so for example there would be a 2 / 5 = 40%
chance that the path could end with a 4x1 line to the finish). The stacks are placed such that the top of one stack will align to the bottom of the next stack. The tips of the stacks are not allowed to intersect.
For example, after step 1 it could look like this:
|x| | | | | | | | | |