a-a a-b a-c aaa aab aac aad aan aao aar aas ab- aba abb abc abd abn abo abr abs ac- aca acb acc acd acn aco acr acs ad- ada adb adc add adn ado adr ads an- ana anb anc and ann ano anr ans aoa aob aoc aod aon aoo aor aos ar- ara arb arc ard arn aro arr ars as- asa asb asc asd asn aso asr ass baa bab bac bad ban bao bar bas bba bbb bbc bbd bbn bbo bbr bbs bca bcb bcc bcd bcn bco bcr bcs bda bdb bdc bdd bdo bdr bds bna bnb bnc bnd bnn bno bnr bns boa bob boc bod bon boo bor bos bra brb brd brn bro brr brs bsa bsb bsc bsd bsn bso bsr bss c-- caa cab cac cad can cao car cas cba cbb cbc cbd cbn cbo cbr cbs cca ccb ccc ccd ccn cco ccr ccs cda cdb cdc cdd cdn cdo cdr cds cn- cna cnb cnc cnd cnn cno cnr cns co- coa cob coc cod con coo cor cos cra crb crc crd crn cro crr crs csa csb csc csd csn cso csr css daa dab dac dad dan dao dar das dba dbb dbc dbd dbn dbo dbr dbs dca dcb dcc dcd dcn dco dcr dcs dda ddb ddc ddd ddn ddo ddr dds dna dnb dnc dnd dnn dno dnr dns doa dob doc dod don doo dor dos dra drb drc drd drn dro drr drs dsa dsb dsc dsd dsn dso dsr dss naa nab nac nad nan nao nar nas nba nbb nbc nbd nbn nbo nbr nbs nca ncb ncc ncd ncn nco ncr ncs nda ndb ndc ndd ndn ndo ndr nds nna nnb nnc nnn nno nns no- noa nob noc nod non noo nor nos nra nrb nrc nrd nrn nro nrr nrs nsa nsb nsc nsd nsn nso nsr nss oaa oab oac oad oan oao oar oas ob- oba obb obc obd obn obo obr obs oc- oca ocb occ ocd ocn oco ocr ocs oda odb odc odd odn odo odr ods on- ona onb onc ond onn ono onr ons oo- ooa oob ooc ood oon ooo oor oos or- ora orb orc ord orn oro orr ors os- osa osb osc osd osn oso osr oss ra- raa rab rac rad ran rao rar ras rba rbb rbc rbd rbn rbo rbr rbs rca rcb rcc rcd rcn rco rcr rcs rda rdb rdc rdd rdn rdo rdr rds rna rnb rnc rnd rnn rno rnr rns roa rob roc rod ron roo ror ros rra rrb rrc rrd rrn rrr rrs rsa rsb rsc rsd rsn rso rsr rss saa sab sac sad san sao sar sas sba sbb sbc sbd sbn sbo sbr sbs sca scb scc scd scn sco scr scs sda sdb sdc sdd sdn sdo sdr sds sna snb snc snd snn sno snr sns soa sob soc sod son soo sor sos sr- sra srb src srd srn sro srr srs ss- ssa ssb ssc ssd ssn sso ssr sss