-al a-a a-b a-c aaa aab aac aaf aak aal aan aar ab- aba abb abc abf abk abl abn abr ac- aca acb acc acf ack acl acn acr af- afa afb afc aff afk afl afn afr aka akb akc akk akl akn akr al- ala alb alc alf alk all aln alr an- ana anb anc anf ank anl ann anr ar- ara arb arc arf ark arl arn arr baa bab bac baf bak bal ban bar bba bbb bbc bbf bbk bbl bbn bbr bca bcb bcc bcf bck bcl bcn bcr bfa bfb bfc bff bfl bfn bfr bka bkb bkc bkf bkk bkl bkn bkr bla blb blc blf blk bll bln blr bna bnb bnc bnf bnk bnl bnn bnr bra brb brf brk brl brn brr c-- caa cab cac caf cak cal can car cba cbb cbc cbf cbk cbl cbn cbr cca ccb ccc ccf cck ccl ccn ccr cfa cfb cfc cff cfk cfl cfn cfr cka ckb ckc cl- cla clb clc clf clk cll cln clr cn- cna cnb cnc cnf cnl cnn cnr cra crb crc crf crk crl crn crr faa fab fac faf fak fal fan far fba fbb fbc fbf fbk fbl fbn fbr fca fcb fcc fcf fck fcl fcn fcr ffa ffc fff ffk ffl ffn ffr fka fkb fkc fkf fkk fkl fla flb flc flf fll fln flr fna fnb fnc fnf fnk fnl fnn fnr fra frb frc frf frk frl frn frr ka- kaa kab kac kaf kak kal kan kar kba kbb kbc kbf kbk kbl kbn kbr kca kcb kcc kck kcl kcn kcr kfa kfc kff kkb kkc kkk kkl kkn kkr kl- kla klb klc klf klr kn- kna knc knf knk knl knn knr kra krc krf krk krl krn krr la- laa lab lac laf lak lal lan lar lba lbb lbc lbf lbk lbl lbr lca lcb lcc lcf lck lcl lcn lcr lfa lfb lfc lff lfk lfl lfn lfr lka lkb lkl lkr lla llb llc llf llk lll lln llr lna lnb lnc lnk lnl lnn lnr lra lrb lrc lrf lrk lrn lrr naa nab nac naf nak nal nan nar nba nbb nbc nbf nbk nbl nbn nbr nca ncb ncc ncf nck ncl ncn ncr nfa nfb nfc nff nfk nfl nfn nfr nka nkc nkf nkk nkn nkr nla nlb nlc nlf nlk nll nln nlr nna nnb nnc nnf nnk nnl nnn nra nrb nrc nrf nrk nrl nrn nrr ra- raa rab rac raf rak ral ran rar rba rbb rbc rbf rbk rbl rbn rbr rca rcb rcc rcf rcl rcn rcr rfa rfb rfc rff rfk rfl rfn rfr rkb rkc rkf rkk rla rlc rlf rll rln rlr rna rnb rnc rnn rnr rra rrb rrc rrf rrk rrl rrn rrr

-ana a-ak aaaa aaab aaac aaaf aaal aaan aaar aaba aabb aabc aabl aaca aacb aacc aacf aack aacl aacn aacr aafa aafb aafc aaff aafl aaka aala aalc aall aana aara aarc abaa abab abac abaf abak abal aban abar abb- abba abbb abbr abca abcb abcc abcf abcl abcn abcr abff abla abra abrc acaa acab acac acan acar acba acbl acca accc accf acfc acfl acla aclc aclr acr- acra acrc acrr afaa afak afan afar afca afcb afcc affa affc afka afkr afla aflc afr- afra afrc akaa akal akan akar akca akka akna akr- akra alaa alac alak alal alan alar alb- alba albc alca alcc alfa alk- alka alkb all- alla alll alln allr alna ana- anaa anab anac anak anal anan anar anba anbb anbl anca ancc anfa ank- anka anla anlc anln anna annb anrc arab arac araf arak aral aran arar arba arc- arca arfa arfb arfc arff arka arla arna arnk arr- arra arrc arrk arrr baaa baaf baak baal baan baar baba babb babr bac- baca bacc back bacn bafc baff bak- baka bakl bakr bala balc balf balk ball bana banc bank bann banr bar- bara barb barc barf bark barn barr bbbb bbfc bbfn bblb bbrc bcaa bcar bcbc bcca bccc bccl bcfc bcra bfca bffl blaa blab blac blak blan blfc blkb blrc bnrr brab brac braf brak bran brca brcb brfc brka brkb brna brrr caaa caab caac caaf caal caan caba cabf cac- caca cacc cack cacr cafa cafb cafc caff cafl caka cala calc calf calk call cana canc cank cann cara carb carc carf cark carl carn carr cbac cbal cbar cbbc cbca cbcc cbcl cbcn cbcr cbfb cbfc cbka cbkl cbkn cbkr cblb cblc cbln cbna cbrl cbrn ccaa ccab ccac ccaf ccar ccba ccbc ccbn ccca cccb cccc cccf cccl ccfa ccfc ccff ccfl ccla cclc ccna ccnb ccnc ccnf ccnr ccra ccrc ccrf ccrl cfaa cfab cfac cfar cfbc cfbn cfbr cfca cfcb cfcf cfcl cfcn cffb cffr cfln cfnb cfnr cfra cfrb cfrn ckac ckan ckbc ckck ckcl ckfr cklf ckln cknb cknc ckrc clab claf clan clar clra cnaa cnac cnbc cnbl cnfa cnna cnrc cnrr crab crac craf cran crar crbc crca crcc crcr crfc crfl crkc crkl crlf crna f--k faaa faac faan faba faca facc fack fafa fafc faff fala falc falk fall faln fana fanc fank fara farb farc fark farl farr fbar fbla fcab fcal fcar fcba fcca fccf fcnl fcra ffar ffcc ffff ffrr fkab flab flac flak flan flcl flna flnb flnc fnac fnar fnlc frab frac frak fran frbc frcc frcn frfc frla kaaa kaab kaaf kaak kaal kaan kaar kaba kabb kabc kabf kabr kacb kacc kacl kafa kafc kaff kafn kafr kaka kakc kakk kakn kala kalb kalc kalf kalk kall kaln kana kanb kanf kann kara karb karf kark karl karn karr kbaa kbab kbac kbak kbal kbar kbba kbbb kbbc kbbf kbbk kbbl kbbr kbca kbcb kbck kbcl kbcr kbfb kbfc kbff kbfk kbfl kbfr kbkb kbkf kbkk kbkl kbkr kbla