a-a a-b a-c aaa aab aac aad aak aao aap aar ab- aba abb abc abd abk abo abp abr ac- aca acb acc acd ack aco acp acr ad- ada adb adc add adk ado adp adr aka akb akc akd akk ako akp akr aoa aob aoc aod aok aoo aop aor ap- apa apb apc apd apk apo app apr ar- ara arb arc ard ark aro arp arr b-p baa bab bac bad bak bao bap bar bba bbb bbc bbd bbk bbo bbp bbr bca bcb bcc bcd bck bco bcp bcr bda bdb bdc bdd bdk bdo bdp bdr bka bkb bkc bkk bko bkp bkr boa bob boc bod bok boo bop bor bpa bpb bpc bpd bpo bpp bpr bra brb brd brk bro brp brr c-- caa cab cac cad cak cao cap car cba cbb cbc cbd cbk cbo cbp cbr cca ccb ccc ccd cck cco ccp ccr cda cdb cdc cdd cdk cdo cdp cdr cka ckb ckc ckd cko co- coa cob coc cod cok coo cop cor cpa cpb cpc cpd cpk cpo cpp cpr cra crb crc crd crk cro crp crr daa dab dac dad dak dao dap dar dba dbb dbc dbd dbk dbo dbp dbr dca dcb dcc dcd dck dco dcp dcr dda ddb ddc ddd ddk ddo ddp ddr dka dkb dkc dkk dko dkp dkr doa dob doc dod dok doo dop dor dpa dpb dpc dpd dpk dpo dpp dpr dra drb drc drd drk dro drp drr ka- kaa kab kac kad kak kao kap kar kba kbb kbc kbd kbk kbo kbp kbr kca kcb kcc kcd kck kcp kcr kda kdb kdc kdk kdo kdp kdr kkb kkc kkk kkp kkr koa kob koc kod kok koo kop kor kpa kpc kpd kpk kpo kpp kpr kra krc krd krk kro krp krr oaa oab oac oad oak oao oap oar ob- oba obb obc obd obk obo obp obr oc- oca ocb occ ocd ock oco ocp ocr oda odb odc odd odo odp odr oka okb okc okd okk oko okp okr oo- ooa oob ooc ood ook ooo oop oor op- opa opb opc opd opk opo opp opr or- ora orb orc ord ork oro orp orr p-p paa pab pac pad pak pao pap par pba pbb pbc pbd pbk pbo pbp pbr pca pcb pcc pcd pck pco pcp pcr pda pdb pdc pdd pdk pdo pdp pdr pka pkb pkc pkd pko pkp pkr poa pob poc pod pok poo pop por ppa ppb ppc ppd ppk ppo ppp ppr pra prb prc prd prk pro prp prr ra- raa rab rac rad rak rao rap rar rba rbb rbc rbd rbk rbo rbp rbr rca rcb rcc rcd rco rcp rcr rda rdb rdc rdd rdo rdp rdr rkb rkc rkk rko rkp roa rob roc rod rok roo rop ror rpa rpb rpc rpd rpk rpo rpp rpr rra rrb rrc rrd rrk rrp rrr

a-ak a-do a-ok aaaa aaab aaac aaad aaap aaar aaba aabb aabc aabd aabp aaca aacb aacc aacd aack aaco aacp aacr aada aadc aaka aaoo aapa aapc aapo aara aarc aard aaro aarp abaa abab abac abad abak abap abar abb- abba abbb abbo abbr abca abcb abcc abcd abcp abcr abda abdo aboa abob abod abok aboo abor abpa abpc abpd abpp abpr abra abrc abro acaa acab acac acad acap acar acba acca accc accd acco accp acda acdb acdc acdp ackd acoa acod acop acor acpa acpd acpr acr- acra acrc acro acrr adaa adab adac adad adak adao adap adar adba adbc adcc adda addc addd addo addr adob adoc adod adok adoo ador adp- adra adro akaa akao akap akar akca akka akko akok akpo akr- akra aoba aoca aokp aopo aora aorb apac apak apao apap apar apba apbr apca apcb apcc apcd apco apcr apda apdd apo- apoc apod apoo apop apor appa appc appd appr apra aprc apro arab arac arad arak arap arar arba arc- arca arco arda ardc ardo arka arko aroa arob arod aroo aror arpa arr- arra arrc arrk arro arrr baaa baad baak baar baba babb babo babr bac- baca bacc back baco bada badb badd bado badr bak- baka bako bakr bapa bapc bapp bar- bara barb barc bard bark baro barr bbad bbbb bbdd bbdo bbpr bbrc bcaa bcap bcar bcbc bcbp bcca bccc bcda bcor bcpp bcra bd-r bdbc bddc bdpc bkpr boab boac boad boak boar boba bobb bobo boca bock boco boda bodb bodo boka boko boob booc bood book boop boor bopa bopp bor- bora bord bork boro borr bpcp bpda bprc bprd brab brac brad brak brao brca brcb brda brdo brka brkb broa brob broc brod brok broo bror brrr c-bo c-cd caaa caab caac caap caba cabo cac- caca cacc cack caco cacr cada cadc cadd cado cadr caka caod caor capa capb capc capd capo capp cara carb carc card cark caro carp carr cbac cbar cbbc cbca cbcc cbcp cbcr cbdb cbdc cbdo cbka cbko cbkr cbpc cbpp cbrd ccaa ccab ccac ccad ccap ccar ccba ccbc ccca cccb cccc cccp ccdc ccdp ccdr ccob ccoc ccod ccpa ccpp ccpr ccra ccrc ccrp cd-r cdaa cdac cdad cdba cdda cddb cddr ckac ckbc ckck ckco ckdo ckoa ckob ckoc ckoo ckor ckpc ckpr ckrc ckrd coad coak coba cobb cobo coca cock coco cocp coda codd cok- coka coko coob cood cook coop copa copd copo copp copr cor- cora corb corc cord cork coro corp corr cpaa cpac cpad cpap cpbc cpca cppa cppd crab crac crap crar crbc crca crcc crcr crda crdc crkc crkp crob croc crod crok croo crop cror crpc d-bo daab daad daap daar daba dabb dabo dabp daca dada dado daka dako dapa dapp dara darb darc dard dark daro darp darr dbar dbcc dbcp dbpc dbpd dcbc dcca