a-a aaa aaf aag aan aas af- afa aff afg afn afs ag- aga agf agg agn ags an- ana anf ang ann ans as- asa asf asg asn ass faa faf fag fan fas ffa fff ffg ffn ffs fga fgf fgg fgn fgs fna fnf fng fnn fns fsa fsf fsg fsn fss gaa gaf gag gan gas gfa gff gfs gga ggg ggn ggs gna gnf gnn gns gsa gsf gsg gsn gss naa naf nag nan nas nfa nff nfn nfs nga ngf ngg ngn ngs nna nnf nng nnn nns nsa nsf nsg nsn nss saa saf sag san sas sfa sff sfg sfn sfs sga sgf sgg sgn sgs sna snf sng snn sns ss- ssa ssf ssg ssn sss