a-a a-b a-c aaa aab aac aad aak aan aar aas ab- aba abb abc abd abk abn abr abs ac- aca acb acc acd ack acn acr acs ad- ada adb adc add adk adn adr ads aka akb akc akd akk akn akr aks an- ana anb anc and ank ann anr ans ar- ara arb arc ard ark arn arr ars as- asa asb asc asd ask asn asr ass baa bab bac bad bak ban bar bas bba bbb bbc bbd bbk bbn bbr bbs bca bcb bcc bcd bck bcn bcr bcs bda bdb bdc bdd bdk bdr bds bka bkb bkc bkk bkn bkr bks bna bnb bnc bnd bnk bnn bnr bns bra brb brd brk brn brr brs bsa bsb bsc bsd bsk bsn bsr bss c-- caa cab cac cad cak can car cas cba cbb cbc cbd cbk cbn cbr cbs cca ccb ccc ccd cck ccn ccr ccs cda cdb cdc cdd cdk cdn cdr cds cka ckb ckc ckd cks cn- cna cnb cnc cnd cnn cnr cns cra crb crc crd crk crn crr crs csa csb csc csd csk csn csr css daa dab dac dad dak dan dar das dba dbb dbc dbd dbk dbn dbr dbs dca dcb dcc dcd dck dcn dcr dcs dda ddb ddc ddd ddk ddn ddr dds dka dkb dkc dkk dkr dks dna dnb dnc dnd dnk dnn dnr dns dra drb drc drd drk drn drr drs dsa dsb dsc dsd dsk dsn dsr dss ka- kaa kab kac kad kak kan kar kas kba kbb kbc kbd kbk kbn kbr kbs kca kcb kcc kcd kck kcn kcr kcs kda kdb kdc kdk kdr kds kkb kkc kkk kkn kkr kks kn- kna knc knd knk knn knr kra krc krd krk krn krr krs ksa ksb ksc ksd ksk ksn ksr kss naa nab nac nad nak nan nar nas nba nbb nbc nbd nbk nbn nbr nbs nca ncb ncc ncd nck ncn ncr ncs nda ndb ndc ndd ndk ndn ndr nds nka nkc nkk nkn nkr nks nna nnb nnc nnk nnn nns nra nrb nrc nrd nrk nrn nrr nrs nsa nsb nsc nsd nsk nsn nsr nss ra- raa rab rac rad rak ran rar ras rba rbb rbc rbd rbk rbn rbr rbs rca rcb rcc rcd rcn rcr rcs rda rdb rdc rdd rdn rdr rds rkb rkc rkk rks rna rnb rnc rnd rnn rnr rns rra rrb rrc rrd rrk rrn rrr rrs rsa rsb rsc rsd rsk rsn rsr rss saa sab sac sad sak san sar sas sba sbb sbc sbd sbk sbn sbr sbs sca scb scc scd sck scn scr scs sda sdb sdc sdd sdk sdn sdr sds sk- ska skb skc skd skk skr sks sna snb snc snd snk snn snr sns sr- sra srb src srd srk srn srr srs ss- ssa ssb ssc ssd ssk ssn ssr sss