The paths in each group are then ordered according to the number of nodes in each path, wherein {HEAD ~ the path} with {TAIL ~ the lowest number} of nodes is placed first 
with
The paths in each group are then ordered according to the number of nodes in each path , wherein { HEAD ~ the path } with { TAIL ~ the lowest number } of nodes is placed first
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH