-er bbb bbc bbe bbk bbo bbr bbt bcb bcc bce bck bco bcr bct be- beb bec bee bek beo ber bet bkb bkc bke bkk bko bkr bkt bob boc boe bok boo bor bot brb bre brk bro brr brt btb btc bte btk bto btr btt c-- cbb cbc cbe cbk cbo cbr cbt ccb ccc cce cck cco ccr cct ce- ceb cec cee cek ceo cer cet ckb ckc cko ckt co- cob coc coe cok coo cor cot crb crc cre crk cro crr crt ctb ctc cte ctk cto ctr ctt ebb ebc ebe ebk ebo ebr ebt ec- ecb ecc ece eck eco ecr ect eeb eec eee eek eeo eer eet ekb ekc eke eko ekr ekt eo- eob eoc eoe eok eoo eor eot erb erc ere erk ero err ert etb etc ete etk eto etr ett k-t kbb kbc kbe kbk kbo kbr kcb kcc kce kck kcr kct ke- keb kec kee kek keo ker ket kkb kkc kke kkk kkr kkt kob koc koe kok koo kor kot krc krk kro krr krt ktb ktc kte ktk kto ktr ktt ob- obb obc obe obk obo obr obt oc- ocb occ ock oco ocr oct oeb oec oee oeo oer oet okb okc oke okk oko okr oo- oob ooc ook ooo oor oot or- orb orc ore ork oro orr ort ot- otb otc ote otk oto otr ott rbb rbc rbe rbk rbo rbr rbt rcb rcc rce rco rcr rct re- reb rec ree rek reo rer ret rkb rkc rke rkk rko rkt rob roc roe rok roo ror rot rrb rrc rrk rrr rrt rtb rtc rte rtk rto rtr rtt tbb tbc tbe tbk tbo tbr tbt tcb tcc tce tck tco tcr tct te- teb tec tee tek teo ter tet tkb tkc tke tkk tko tkr tkt to- tob toc toe tok too tor tot trb trc tre trk tro trr trt ttb ttc tte ttk tto ttr ttt

bbbb bbeb bbet bbrc bcbc bccc bcec bcer bcet bcor bctc bebb bebe bebo beck beeb beek beer beet beke beko beo- beok beor beot berc bere berk bero berr bert betc bete beto bett bobb bobe bobo boce bock boco boec boee boeo boer boet boke boko boob booc booe book boor boot bor- bore bork boro borr bort botb bote boto bott brcb brce breb brec bree brek breo brer bret brkb brob broc broe brok broo bror brot brrr brtc btcc btec btek btob btor btrc btrt bttb c-bo cbbc cbcc cbce cbcr cbct cbec cbee cber cbet cbko cbkr cbot cbre cbrt cbtc ccbc cccb cccc ccee ccob ccoc ccrc ccre ccrt cctb cctc cctt cec- cece ceco cect ceeb ceec ceke ceor cer- cerc cere cero cert cet- cete ceto ckbc ckbe ckck ckco cker ckob ckoc ckoo ckor ckot ckrc cktb cobb cobe cobo coce cock coco coct cok- coke coko coob cook coot cor- corb corc core cork coro corr cort cotb cotc cote coto cott crbc crcc crce crcr cre- creb crec cree creo cret crkc crob croc croe crok croo cror crot crrt crtc ctec ctor ctot ctrc ebbc ebbo ebbr ebcc eber eboe eboo ebor ebro ecbc ecbe eccb eccc ecce ecco ecct ecko eco- ecot ecrc ecrr ect- ectc ecto eeee eeke eeoc eerc eero eetc eete ekco ekeb ekek eker eket eore eotc eoto erbb erbe ercc erce ereb erec erer eret erke erob eroc eroe eroo errc erre erro etbc etbr etcc etco etec etee eter etoe etok etre etro ette etto kbbb kbbc kbbe kbbk kbbo kbbr kbbt kbcb kbce kbck kbco kbcr kbct kbeb kbec kbee kbek kbeo kber kbet kbkb kbkk kbko kbkr kbob kboc kboe kbok kboo kbot kbrb kbrc kbre kbrk kbro kbrt kbtb kbtc kbte kbtk kbto kbtr kbtt kcbc kcbk kcbr kccb kccc kcck kccr kcct kceb kcec kcee kceo kcet kckc kckk kcko kckr kcob kcoe kcor kcot kcrc kcro kcrr kcrt kctb kctc kcte kcto kebb kebc kebe kebr kebt keck keco kecr keek keer keet kekb kekc keke keko keok ker- kerb kerc kere kerk kero kerr kert ket- ketc kete ketk keto ketr kett kkbb kkbe kkbo kkbr kkbt kkcb kkck kkco kkcr kkct kkkk kkob kkoo kkor kkot kkrb kkrc kkre kkrk kkro kkrr kkrt kktc kktk kobb kobc kobe kobk kobo kobr kocb kock koct kokb kokc koke kokk koko kokr koob kooc kook kooo koor koot korb korc kore kork koro korr kort kotb kotc kote kotk koto kotr kott krbb krbe krbk krbr krbt krcb krcc krce krco kreb krec kree krek kreo kret krkc krke krkk krko krkr krob kroc kroe krok kroo kror krrb krrc krre krrk krro krrr krrt krtc krtk krto krtr ktbb ktbc ktbr ktbt ktcc ktce ktck ktco ktcr ktec ktee ktek ktkb ktkc ktke ktkk ktko ktkr ktkt ktob ktoc ktoe ktok ktoo ktor ktot ktrb ktrc ktre ktrk ktro ktrr ktrt kttc kttk ktto kttr kttt o-eo obbo obec ober obet obkb oboe obok obor obot obre obro ocbc occc occt oce ocee ocet ocke ocre ocro ocrr oct- octe octo oec- oecc oeec oere oker oket okko okok okor okot okre okro okto oobe oocr ooer oooo oore oort ootb orbb orbe orbo orce orco ore- oreb orec orek oreo orer orke orko oro- oroe orok oror orot orro ortc orte orto otee oter oto- otoe otok otoo otor otre otro otte otto rbbb rbbr rcbc rcbo rccb rccc rcet rctc rebb rebe rebk rebo recc rece reck recr rect reeb reek reet reke reko rekt reot rere rero rert rete reto retr rett rob- robb robe robo robt rocc roce rock roco roer roet roke rokk roko rokr roob rook roor root rorc rore rork roro rort rotc rote rotk roto rotr rott rrrr rtcc rtce rtee tbcb tbcc tbce tbrb tccc tctc tebo teck teco tecr tect teec teek