a-a a-b a-c aaa aab aac aad aak aao aar aas aav ab- aba abb abc abd abk abo abr abs abv ac- aca acb acc acd ack aco acr acs acv ad- ada adb adc add adk ado adr ads adv aka akb akc akd akk ako akr aks akv aoa aob aoc aod aok aoo aor aos aov ar- ara arb arc ard ark aro arr ars arv as- asa asb asc asd ask aso asr ass asv av- ava avb avc avd avk avo avr avs baa bab bac bad bak bao bar bas bav bba bbb bbc bbd bbk bbo bbr bbs bca bcb bcc bcd bck bco bcr bcs bcv bda bdb bdc bdd bdk bdo bdr bds bdv bka bkb bkc bkk bko bkr bks bkv boa bob boc bod bok boo bor bos bov bra brb brd brk bro brr brs brv bsa bsb bsc bsd bsk bso bsr bss bsv bva bvb bvc bvd bvk bvo bvr bvs bvv c-- caa cab cac cad cak cao car cas cav cba cbb cbc cbd cbk cbo cbr cbs cbv cca ccb ccc ccd cck cco ccr ccs ccv cda cdb cdc cdd cdk cdo cdr cds cdv cka ckb ckc ckd cko cks co- coa cob coc cod cok coo cor cos cov cra crb crc crd crk cro crr crs crv csa csb csc csd csk cso csr css csv cva cvb cvc cvd cvk cvo cvr cvs cvv daa dab dac dad dak dao dar das dav dba dbb dbc dbd dbk dbo dbr dbs dbv dca dcb dcc dcd dck dco dcr dcs dcv dda ddb ddc ddd ddk ddo ddr dds dka dkb dkc dkk dko dkr dks doa dob doc dod dok doo dor dos dov dra drb drc drd drk dro drr drs drv dsa dsb dsc dsd dsk dso dsr dss dsv dva dvb dvc dvd dvk dvr dvs ka- kaa kab kac kad kak kao kar kas kav kba kbb kbc kbd kbk kbo kbr kbs kca kcb kcc kcd kck kcr kcs kda kdb kdc kdk kdo kdr kds kkb kkc kkk kkr kks kkv koa kob koc kod kok koo kor kos kra krc krd krk kro krr krs krv ksa ksb ksc ksd ksk kso ksr kss ksv kva kvb kvk kvo kvr kvs kvv oaa oab oac oad oak oao oar oas oav ob- oba obb obc obd obk obo obr obs obv oc- oca ocb occ ocd ock oco ocr ocs ocv oda odb odc odd odo odr ods odv oka okb okc okd okk oko okr oks oo- ooa oob ooc ood ook ooo oor oos oov or- ora orb orc ord ork oro orr ors orv os- osa osb osc osd osk oso osr oss osv ov- ova ovb ovc ovd ovo ovs ovv ra- raa rab rac rad rak rao rar ras rav rba rbb rbc rbd rbk rbo rbr rbs rca rcb rcc rcd rco rcr rcs rcv rda rdb rdc rdd rdo rdr rds rdv rkb rkc rkk rko rks rkv roa rob roc rod rok roo ror ros rov rra rrb rrc rrd rrk rrr rrs rsa rsb rsc rsd rsk rso rsr rss rsv rva rvb rvc rvd rvo rvr rvs rvv saa sab sac sad sak sao sar sas sav sba sbb sbc sbd sbk sbo sbr sbs sbv sca scb scc scd sck sco scr scs scv sda sdb sdc sdd sdk sdo sdr sds sdv sk- ska skb skc skd skk sko skr sks soa sob soc sod sok soo sor sos sov sr- sra srb src srd srk sro srr srs srv ss- ssa ssb ssc ssd ssk sso ssr sss ssv sva svb svc svd svk svo svr svs svv v-a vaa vab vac vad vak vao var vas vav vba vbc vbd vbk vbo vbr vbs vbv vca vcc vcd vco vcr vcs vdb vdc vdd vdk vdo vdr vds vdv vka vkb voa vob voc vod vok voo vor vos vov vra vrb vrc vrd vrk vrr vrs vsa vsb vsc vsd vsk vso vsr vss vsv vva vvb vvc vvo vvr vvs vvv