Chose a building from the list.
-5-7-15-18-19-21-22-23-29-35-36-37-39-40-group4(41,42,43)-

-44-46-48-57-59-60-80-82-90-93-94-98-100-101-122-

-123-129-134-135-136-137-138-139-144-Tunnels-Cemetery-

Building #137 kitchen for group 3 and the medical building, 136. The other two buildings of group 3 are long gone, but the underground corridors to the dining hall are still present.