X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
NE
SE
SW
NW
0/12

How to use
Select the 12 squares that have sandbags on them, then click "Show Grid" to view which tiles have to be lit up.

Based on the work of TrueJole.