-al a-a a-b a-c a-t aaa aab aac aak aal aar aat ab- aba abb abc abk abl abr abt ac- aca acb acc ack acl acr act aka akb akc akk akl akr al- ala alb alc alk all alr alt ar- ara arb arc ark arl arr art at- ata atb atc atl atr att baa bab bac bak bal bar bat bba bbb bbc bbk bbl bbr bbt bca bcb bcc bck bcl bcr bct bka bkb bkc bkk bkl bkr bkt bla blb blc blk bll blr blt bra brb brk brl brr brt bta btb btc btk btl btr btt c-- caa cab cac cak cal car cat cba cbb cbc cbk cbl cbr cbt cca ccb ccc cck ccl ccr cct cka ckb ckc ckt cl- cla clb clc clk cll clr clt cra crb crc crk crl crr crt cta ctb ctc ctk ctl ctr ctt k-t ka- kaa kab kac kak kal kar kat kba kbb kbc kbk kbl kbr kca kcb kcc kck kcl kcr kct kkb kkc kkk kkl kkr kkt kl- kla klb klc klr klt kra krc krk krl krr krt kta ktb ktc ktk ktl ktr ktt la- laa lab lac lak lal lar lat lba lbb lbc lbk lbl lbr lbt lca lcb lcc lck lcl lcr lct lka lkb lkl lkr lkt lla llb llc llk lll llr llt lra lrb lrc lrk lrr lrt lta ltb ltc ltk ltl ltr ltt ra- raa rab rac rak ral rar rat rba rbb rbc rbk rbl rbr rbt rca rcb rcc rcl rcr rct rkb rkc rkk rkt rla rlc rll rlr rlt rra rrb rrc rrk rrl rrr rrt rta rtb rtc rtk rtl rtr rtt taa tab tac tak tal tar tat tba tbb tbc tbk tbl tbr tbt tca tcb tcc tck tcl tcr tct tka tkb tkc tkk tkl tkr tkt tla tlc tlk tll tlr tlt tra trb trc trk trl trr trt tta ttb ttc ttk ttl ttr ttt

a-ak aaaa aaab aaac aaal aaar aaba aabb aabc aabl aabt aaca aacb aacc aack aacl aacr aact aaka aala aalc aall aara aarc aart aata aatc aatk aatt abaa abab abac abak abal abar abat abb- abba abbb abbr abbt abca abcb abcc abcl abcr abct abla abra abrc abta ac-t acaa acab acac acar acat acba acbl acca accc acct acla aclc aclr acr- acra acrc acrr acta actc actl actt akaa akal akar akca akka akr- akra alaa alac alak alal alar alat alb- alba albc alca alcc alk- alka alkb all- alla alll allr alta arab arac arak aral arar arat arba arc- arca arct arka arla arr- arra arrc arrk arrr arrt arta artc artr at-l at-t ataa atab atac atak atal atar atat atca atcc atck atcl atcr atka atkt atla atra atrc atrk atta attr baaa baak baal baar baat baba babb babr bac- baca bacc back bact bak- baka bakl bakr bakt bala balc balk ball balt bar- bara barb barc bark barr bart bata batc batt bbbb bblb bbrc bcaa bcar bcat bcbc bcca bccc bccl bcra bctc blaa blab blac blak blat blbt blkb blrc brab brac brak brat brca brcb brka brkb brrr brtc btaa btcc btcl btla btrc btrt bttb caaa caab caac caal caat caba cac- caca cacc cack cacr caka cala calc calk call calt cara carb carc cark carl carr cart cat- cata catb catc catt cbac cbal cbar cbat cbbc cbca cbcc cbcl cbcr cbct cbka cbkl cbkr cblb cblc cbrl cbrt cbta cbtc cbtl ccaa ccab ccac ccar ccat ccba ccbc ccca cccb cccc cccl ccla cclc ccra ccrc ccrl ccrt cctb cctc cctl cctt ckac ckat ckbc ckck ckcl ckrc cktb clab clar clat clra cltb cltc crab crac crar crat crbc crca crcc crcr crkc crkl crrt crtc crtl ctab ctal ctba ctca ctrc ctrl ctta kaaa kaab kaak kaal kaar kaat kaba kabb kabc kabr kacb kacc kacl kact kaka kakc kakk kakt kala kalb kalc kalk kall kalt kara karb kark karl karr kart kat- kata katb katc katk katl katr katt kbaa kbab kbac kbak kbal kbar kbat kbba kbbb kbbc kbbk kbbl kbbr kbbt kbca kbcb kbck kbcl kbcr kbct kbkb kbkk kbkl kbkr kbla kblb kbll kblr kblt kbra kbrb kbrc kbrk kbrl kbrt kbta kbtb kbtc kbtk kbtl kbtr kbtt kcaa kcab kcac kcal kcar kcat kcba kcbc kcbk kcbl kcbr kcca kccb kccc kcck kccl kccr kcct kckc kckk kckl kckr kcla kclc kclk kcll kclr kclt kcrc kcrr kcrt kcta kctb kctc kkaa kkac kkal kkar kkat kkba kkbb kkbl kkbr kkbt kkcb kkck kkcl kkcr kkct kkkk kklb kklc kkll kkrb kkrc kkrk kkrl kkrr kkrt kktc kktk kktl klaa klab klac klak klal klar klat klbb klbc klbl klbt klca klcb klcc klck klcl klcr klka klkc klkk klkl klkr klla kllb kllc kllk klrc klrk klrr kltc kltk kltr kltt krab krac krak kral krar krat krba krbb krbk krbl krbr krbt krca krcb krcc krcl krka krkc krkk krkr krla krlc krlt krrb krrc krrk krrl krrr krrt krta krtc krtk krtr ktaa ktak ktal ktar ktat ktba ktbb ktbc ktbl ktbr ktbt ktcc ktck ktcl ktcr ktkb ktkc ktkk ktkr ktkt ktla ktlb ktlk ktlr ktlt ktrb ktrc ktrk ktrl ktrr ktrt kttc kttk kttr kttt laaa laac laak laal laar laat laba labr laca lacc lack lacl lact laka lala lall lara larb larc lark larr lart lata latc latt lbar lbcc lblr lbrt lcac lcat lcbc lcca lccc lcra lcrl lctl lkab lkal llat llcc lllc llll lrac lral lrat lrba lrrc lrrr lrta ltac ltbl ltcc ltra lttc lttr raab raak raat raba rabb rabk rabl rac- raca racc rack ract raka rakk rakt rala ralb rall ralt rara rarb rark rata ratk ratt rbbb rbbr rbcl rcac rcbc rccb rccc rctc rlab rrat rrrr rtca rtcc rtlt taa- taal taar taat taba tabb tabc tabl