a-a a-b a-c aaa aab aac aam aan aao aar aas ab- aba abb abc abm abn abo abr abs ac- aca acb acc acm acn aco acr acs ama amb amc amm amn amo amr ams an- ana anb anc anm ann ano anr ans aoa aob aoc aom aon aoo aor aos ar- ara arb arc arm arn aro arr ars as- asa asb asc asm asn aso asr ass baa bab bac bam ban bao bar bas bba bbb bbc bbm bbn bbo bbr bbs bca bcb bcc bcm bcn bco bcr bcs bma bmb bmc bmm bmn bmo bmr bms bna bnb bnc bnn bno bnr bns boa bob boc bom bon boo bor bos bra brb brm brn bro brr brs bsa bsb bsc bsm bsn bso bsr bss c-- caa cab cac cam can cao car cas cba cbb cbc cbm cbn cbo cbr cbs cca ccb ccc ccm ccn cco ccr ccs cma cmb cmc cmm cmn cmo cmr cms cn- cna cnb cnc cnm cnn cno cnr cns co- coa cob coc com con coo cor cos cra crb crc crm crn cro crr crs csa csb csc csm csn cso csr css m-o m-r maa mab mac mam man mao mar mas mba mbb mbc mbm mbo mbr mbs mc- mca mcb mcc mcm mcn mco mcr mcs mma mmb mmc mmm mmn mmo mmr mms mna mnb mnc mnm mnn mno mnr mns moa mob moc mom mon moo mor mos mra mrb mrc mrm mrn mro mrr mrs msa msb msc msm msn mso msr mss naa nab nac nam nan nao nar nas nba nbb nbc nbm nbn nbo nbr nbs nca ncb ncc ncm ncn nco ncr ncs nma nmb nmc nmm nmn nmo nmr nms nna nnb nnc nnm nnn nno nns no- noa nob noc nom non noo nor nos nra nrb nrc nrm nrn nro nrr nrs nsa nsb nsc nsm nsn nso nsr nss oaa oab oac oam oan oao oar oas ob- oba obb obc obm obn obo obr obs oc- oca ocb occ ocm ocn oco ocr ocs om- oma omb omc omm omn omo omr oms on- ona onb onc onn ono onr ons oo- ooa oob ooc oom oon ooo oor oos or- ora orb orc orm orn oro orr ors os- osa osb osc osm osn oso osr oss ra- raa rab rac ram ran rao rar ras rba rbb rbc rbm rbn rbo rbr rbs rca rcb rcc rcm rcn rco rcr rcs rma rmb rmc rmm rmn rmo rmr rms rna rnb rnc rnm rnn rno rnr rns roa rob roc rom ron roo ror ros rra rrb rrc rrm rrn rrr rrs rsa rsb rsc rsm rsn rso rsr rss saa sab sac sam san sao sar sas sba sbb sbc sbm sbn sbo sbr sbs sca scb scc scm scn sco scr scs sma smb smc smm smn smo smr sms sna snb snc snm snn sno snr sns soa sob soc som son soo sor sos sr- sra srb src srm srn sro srr srs ss- ssa ssb ssc ssm ssn sso ssr sss