155534

I worked out that to get the smallest number for each one, you have to point the snake directly up, and if you want to get the highest possible number for each one you needed to point the snake directly down. I also worked out that there are 32 different positions for each square, that's 512 in total! I know this, because there are different ways the worm can be positioned and you can put each one, North, East, South, West.