Grid:

  0 1 2 3 4 5 6 7 8 9
A . X . . . . . . . .
B . X . X X X . X X .
C . X X X . X . X . .
D . . . . . X . X X .
E . X X . . X . X . .
F . X . X X X . X . .
G . X X X . X . X . .
H . X . X . X . X . .
I . X . X . X X X X .
J . X . . . . . . . .


Grid point C3: exits are S and E, so draw them Open.
B8: Exits are only W
G3: Exits are N, S, W
Entrance: A1 (occupies a space on the edge)
Exit: J1