Furthermore, the number of {HEAD ~ conductive segments} in {TAIL ~ a given edge} of a given row may be odd or even 
Furthermore , the number of { HEAD ~ conductive segments } in { TAIL ~ a given edge } of a given row may be odd or even
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH