a-a a-b a-c aaa aab aac aaf aak aao aap aar ab- aba abb abc abf abk abo abp abr ac- aca acb acc acf ack aco acp acr af- afa afb afc aff afk afo afp afr aka akb akc akk ako akp akr aoa aob aoc aof aok aoo aop aor ap- apa apb apc apf apk apo app apr ar- ara arb arc arf ark aro arp arr b-p baa bab bac baf bak bao bap bar bba bbb bbc bbf bbk bbo bbp bbr bca bcb bcc bcf bck bco bcp bcr bfa bfb bfc bff bfo bfp bfr bka bkb bkc bkf bkk bko bkp bkr boa bob boc bof bok boo bop bor bpa bpb bpc bpf bpo bpp bpr bra brb brf brk bro brp brr c-- caa cab cac caf cak cao cap car cba cbb cbc cbf cbk cbo cbp cbr cca ccb ccc ccf cck cco ccp ccr cfa cfb cfc cff cfk cfo cfp cfr cka ckb ckc cko co- coa cob coc cof cok coo cop cor cpa cpb cpc cpf cpk cpo cpp cpr cra crb crc crf crk cro crp crr faa fab fac faf fak fao fap far fba fbb fbc fbf fbk fbo fbp fbr fca fcb fcc fcf fck fco fcp fcr ffa ffc fff ffk ffo ffp ffr fka fkb fkc fkf fkk fkp foa fob foc fof fok foo fop for fpa fpb fpc fpk fpo fpp fpr fra frb frc frf frk fro frp frr ka- kaa kab kac kaf kak kao kap kar kba kbb kbc kbf kbk kbo kbp kbr kca kcb kcc kck kcp kcr kfa kfc kff kfo kkb kkc kkk kkp kkr koa kob koc kof kok koo kop kor kpa kpc kpf kpk kpo kpp kpr kra krc krf krk kro krp krr oaa oab oac oaf oak oao oap oar ob- oba obb obc obf obk obo obp obr oc- oca ocb occ ocf ock oco ocp ocr of- ofa ofb ofc off ofo ofp ofr oka okb okc okk oko okp okr oo- ooa oob ooc oof ook ooo oop oor op- opa opb opc opf opk opo opp opr or- ora orb orc orf ork oro orp orr p-p paa pab pac paf pak pao pap par pba pbb pbc pbf pbk pbo pbp pbr pca pcb pcc pcf pck pco pcp pcr pfa pfb pfc pff pfk pfo pfp pfr pka pkb pkc pkf pko pkp pkr poa pob poc pof pok poo pop por ppa ppb ppc ppf ppk ppo ppp ppr pra prb prc prf prk pro prp prr ra- raa rab rac raf rak rao rap rar rba rbb rbc rbf rbk rbo rbp rbr rca rcb rcc rcf rco rcp rcr rfa rfb rfc rff rfk rfo rfp rfr rkb rkc rkf rkk rko rkp roa rob roc rof rok roo rop ror rpa rpb rpc rpf rpk rpo rpp rpr rra rrb rrc rrf rrk rrp rrr

a-ak a-ok aaaa aaab aaac aaaf aaap aaar aaba aabb aabc aabp aaca aacb aacc aacf aack aaco aacp aacr aafa aafb aafc aaff aaka aaoo aapa aapc aapo aara aarc aaro aarp abaa abab abac abaf abak abap abar abb- abba abbb abbo abbr abca abcb abcc abcf abcp abcr abff aboa abob abof abok aboo abor abpa abpc abpp abpr abra abrc abro acaa acab acac acap acar acba acca accc accf acco accp acfc acoa acop acor acpa acpr acr- acra acrc acro acrr afaa afak afao afap afar afca afcb afcc affa affc affo afka afkr afoa afoo afor afpa afpc afr- afra afrc afro 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 apco apcr apfa apfc apfo apo- apoc apof apoo apop apor appa appc appr apra aprc apro arab arac araf arak arap arar arba arc- arca arco arfa arfb arfc arff arka arko aroa arob aroo aror arpa arr- arra arrc arrk arro arrr baaa baaf baak baar baba babb babo babr bac- baca bacc back baco bafc baff bafo bak- baka bako bakr bapa bapc bapp bar- bara barb barc barf bark baro barr bbbb bbfc bbpr bbrc bcaa bcap bcar bcbc bcbp bcca bccc bcfc bcof bcor bcpp bcra bfca bfpo bfpp bkpr boab boac boak boar boba bobb bobo boca bock boco bofa boff boka boko boob booc boof book boop boor bopa bopp bor- bora borf bork boro borr bpcp bpfc bprc brab brac braf brak brao brca brcb brfc brka brkb broa brob broc brok broo bror brrr c-bo caaa caab caac caaf caap caba cabf cabo cac- caca cacc cack caco cacr cafa cafb cafc caff caka caor capa capb capc capo capp cara carb carc carf cark caro carp carr cbac cbar cbbc cbca cbcc cbcp cbcr cbfb cbfc cbka cbko cbkr cbpc cbpp ccaa ccab ccac ccaf ccap ccar ccba ccbc ccca cccb cccc cccf cccp ccfa ccfc ccff ccob ccoc ccpa ccpp ccpr ccra ccrc ccrf ccrp cfaa cfab cfac cfao cfar cfbc cfbr cfca cfcb cfcf cfco cffb cffr cfoa cfor cfpa cfpo cfpr cfra cfrb cfrp ckac ckbc ckck ckco ckfr ckoa ckob ckoc ckoo ckor ckpc ckpr ckrc coak coba cobb cobo coca cock coco cocp cofc coff cok- coka coko coob coof cook coop copa copo copp copr cor- cora corb corc corf cork coro corp corr cpaa cpac cpaf cpap cpbc cpca cpff cppa crab crac craf crap crar crbc crca crcc crcr crfc crkc crkp crob croc crok croo crop cror crpc f--k faaa faac faap faba fabo faca facc fack facp fafa fafc faff fafo fako fapa fapp fara farb farc fark faro farp farr fbar fbop fcab fcap fcar fcba fcca fccf fccp fcpa fcra ffar ffcc ffff ffrr fkab fkbp foaf foak foar foba foca fock foco fofo foof fook fopp for- fora forb