a-a a-b a-c aaa aab aac aak aam aar aas ab- aba abb abc abk abm abr abs ac- aca acb acc ack acm acr acs aka akb akc akk akm akr aks ama amb amc amk amm amr ams ar- ara arb arc ark arm arr ars as- asa asb asc ask asm asr ass baa bab bac bak bam bar bas bba bbb bbc bbk bbm bbr bbs bca bcb bcc bck bcm bcr bcs bka bkb bkc bkk bkm bkr bks bma bmb bmc bmk bmm bmr bms bra brb brk brm brr brs bsa bsb bsc bsk bsm bsr bss c-- caa cab cac cak cam car cas cba cbb cbc cbk cbm cbr cbs cca ccb ccc cck ccm ccr ccs cka ckb ckc ckm cks cma cmb cmc cmk cmm cmr cms cra crb crc crk crm crr crs csa csb csc csk csm csr css ka- kaa kab kac kak kam kar kas kba kbb kbc kbk kbm kbr kbs kca kcb kcc kck kcm kcr kcs kkb kkc kkk kkm kkr kks kma kmb kmc kmk kmm kms kra krc krk krr krs ksa ksb ksc ksk ksm ksr kss m-r maa mab mac mak mam mar mas mba mbb mbc mbk mbm mbr mbs mc- mca mcb mcc mck mcm mcr mcs mka mkb mkc mkk mkm mkr mks mma mmb mmc mmk mmm mmr mms mra mrb mrc mrk mrm mrr mrs msa msb msc msk msm msr mss ra- raa rab rac rak ram rar ras rba rbb rbc rbk rbm rbr rbs rca rcb rcc rcm rcr rcs rkb rkc rkk rkm rks rma rmb rmc rmm rmr rms rra rrb rrc rrk rrm rrr rrs rsa rsb rsc rsk rsm rsr rss saa sab sac sak sam sar sas sba sbb sbc sbk sbm sbr sbs sca scb scc sck scm scr scs sk- ska skb skc skk skm skr sks sma smb smc smk smm smr sms sr- sra srb src srk srm srr srs ss- ssa ssb ssc ssk ssm ssr sss