The main portion includes {HEAD ~ a lowermost floor}, corner posts, lower peripheral perches, {TAIL ~ a pair} of lower internal perches, an uppermost floor, upper peripheral perches, a pair of upper internal perches, and a ceiling 
The main portion includes { HEAD ~ a lowermost floor } , corner posts , lower peripheral perches , { TAIL ~ a pair } of lower internal perches , an uppermost floor , upper peripheral perches , a pair of upper internal perches , and a ceiling
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH