a-a a-b a-c aaa aab aac aag aan aao aar aas ab- aba abb abc abg abn abo abr abs ac- aca acb acc acg acn aco acr acs ag- aga agb agc agg agn ago agr ags an- ana anb anc ang ann ano anr ans aoa aob aoc aog aon aoo aor aos ar- ara arb arc arg arn aro arr ars as- asa asb asc asg asn aso asr ass baa bab bac bag ban bao bar bas bba bbb bbc bbg bbn bbo bbr bbs bca bcb bcc bcg bcn bco bcr bcs bga bgb bgc bgg bgn bgo bgr bgs bna bnb bnc bng bnn bno bnr bns boa bob boc bog bon boo bor bos bra brb brg brn bro brr brs bsa bsb bsc bsg bsn bso bsr bss c-- caa cab cac cag can cao car cas cba cbb cbc cbg cbn cbo cbr cbs cca ccb ccc ccg ccn cco ccr ccs cga cgb cgc cgg cgn cgo cgr cgs cn- cna cnb cnc cng cnn cno cnr cns co- coa cob coc cog con coo cor cos cra crb crc crg crn cro crr crs csa csb csc csg csn cso csr css gaa gab gac gag gan gao gar gas gba gbc gbg gbn gbo gbr gbs gca gcb gcc gcg gcn gco gcr gcs gga ggb ggc ggg ggn ggo ggr ggs gna gnb gnc gnn gno gnr gns goa gob goc gog gon goo gor gos gra grb grc grg grn gro grr grs gsa gsb gsc gsg gsn gso gsr gss naa nab nac nag nan nao nar nas nba nbb nbc nbg nbn nbo nbr nbs nca ncb ncc ncg ncn nco ncr ncs nga ngb ngc ngg ngn ngo ngs nna nnb nnc nng nnn nno nns no- noa nob noc nog non noo nor nos nra nrb nrc nrg nrn nro nrr nrs nsa nsb nsc nsg nsn nso nsr nss oaa oab oac oag oan oao oar oas ob- oba obb obc obg obn obo obr obs oc- oca ocb occ ocg ocn oco ocr ocs oga ogc ogg ogn ogo ogs on- ona onb onc ong onn ono onr ons oo- ooa oob ooc oog oon ooo oor oos or- ora orb orc org orn oro orr ors os- osa osb osc osg osn oso osr oss ra- raa rab rac rag ran rao rar ras rba rbb rbc rbg rbn rbo rbr rbs rca rcb rcc rcg rcn rco rcr rcs rga rgb rgc rgg rgn rgo rgr rgs rna rnb rnc rng rnn rno rnr rns roa rob roc rog ron roo ror ros rra rrb rrc rrg rrn rrr rrs rsa rsb rsc rsg rsn rso rsr rss saa sab sac sag san sao sar sas sba sbb sbc sbg sbn sbo sbr sbs sca scb scc scg scn sco scr scs sga sgb sgc sgg sgn sgo sgr sgs sna snb snc sng snn sno snr sns soa sob soc sog son soo sor sos sr- sra srb src srg srn sro srr srs ss- ssa ssb ssc ssg ssn sso ssr sss