{HEAD ~ The expected optimal results} are {TAIL ~ the quick generation} of large number of sequences for smearing, simple implementation, thus low cost 
are
{ HEAD ~ The expected optimal results } are { TAIL ~ the quick generation } of large number of sequences for smearing , simple implementation , thus low cost
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH