4 exits
	1 512 	north west
	0 1 		south west
	0 512 	north east
	1 1		south east

4 entries

1 512 	north west 
  3 routes
	TO 0 1
	2 route segments
		1 512 256
		0 256 1
	TO 0 512
	2 route segments
		1 512 256
		0 256 512
	TO 1 1
	1 route segment
		1 512 1
			
0 1 	south west
  3 routes
	TO 1 512
	2 route segments
		0 1 256
		1 256 512
	TO 0 512
	1 route segment
		0 1 512
	TO 1 1
	2 route segments
		0 1 256
		1 256 1
	
		
0 512 	north east
  3 routes
	TO 0 1
	1 route segment
		0 512 1
	TO 1 512
	2 route segments
		0 512 256
		1 256 512
	TO 1 1
	2 route segments
		0 512 256
		1 256 1

1 1		south east
  3 routes
	TO 1 512
	1 route segment
		1 1 512
	TO 0 1
	2 route segments
		1 1 256
		0 256 1
	TO 0 512
	2 route segments
		1 1 256
		0 256 512