-er a-a a-b a-c a-t aaa aab aac aae aan aao aar aat aau ab- aba abb abc abe abn abo abr abt abu ac- aca acb acc ace acn aco acr act acu aea aeb aec aee aen aeo aer aet aeu an- ana anb anc ane ann ano anr ant anu aoa aob aoc aoe aon aoo aor aot aou ar- ara arb arc are arn aro arr art aru at- ata atb atc ate atn ato atr att atu au- aua aub auc aue aun auo aur aut b-u baa bab bac bae ban bao bar bat bau bba bbb bbc bbe bbn bbo bbr bbt bbu bca bcb bcc bce bcn bco bcr bct bcu be- bea beb bec bee ben beo ber bet beu bna bnb bnc bne bnn bno bnr bnt bnu boa bob boc boe bon boo bor bot bou bra brb bre brn bro brr brt bru bta btb btc bte btn bto btr btt btu bua bub buc bue bun buo bur but buu c-- caa cab cac cae can cao car cat cau cba cbb cbc cbe cbn cbo cbr cbt cbu cca ccb ccc cce ccn cco ccr cct ccu ce- cea ceb cec cee cen ceo cer cet ceu cn- cna cnb cnc cne cnn cno cnr cnt cnu co- coa cob coc coe con coo cor cot cou cra crb crc cre crn cro crr crt cru cta ctb ctc cte ctn cto ctr ctt ctu cua cub cuc cue cun cuo cur cut cuu eaa eab eac eae ean eao ear eat eau eba ebb ebc ebe ebn ebo ebr ebt ebu ec- eca ecb ecc ece ecn eco ecr ect ecu eea eeb eec eee een eeo eer eet en- ena enb enc ene enn eno enr ent enu eo- eoa eob eoc eoe eon eoo eor eot eou era erb erc ere ern ero err ert eru eta etb etc ete etn eto etr ett etu eu- eua eub euc eue eun eur eut naa nab nac nae nan nao nar nat nau nba nbb nbc nbe nbn nbo nbr nbt nbu nca ncb ncc nce ncn nco ncr nct ncu ne- nea neb nec nee nen neo ner net neu nna nnb nnc nne nnn nno nnt nnu no- noa nob noc noe non noo nor not nou nra nrb nrc nre nrn nro nrr nrt nru nta ntb ntc nte ntn nto ntr ntt ntu nua nub nuc nue nun nuo nur nut nuu oaa oab oac oae oan oao oar oat oau ob- oba obb obc obe obn obo obr obt obu oc- oca ocb occ ocn oco ocr oct ocu oea oeb oec oee oen oeo oer oet on- ona onb onc one onn ono onr ont onu oo- ooa oob ooc oon ooo oor oot or- ora orb orc ore orn oro orr ort oru ot- ota otb otc ote otn oto otr ott otu ou- oua ouc oue oun ouo our out ra- raa rab rac rae ran rao rar rat rau rba rbb rbc rbe rbn rbo rbr rbt rbu rca rcb rcc rce rcn rco rcr rct rcu re- rea reb rec ree ren reo rer ret reu rna rnb rnc rnn rno rnr rnt rnu roa rob roc roe ron roo ror rot rou rra rrb rrc rrn rrr rrt rru rta rtb rtc rte rtn rto rtr rtt rtu rua rub ruc rue run ruo rur rut ruu taa tab tac tae tan tao tar tat tau tba tbb tbc tbe tbn tbo tbr tbt tbu tca tcb tcc tce tcn tco tcr tct tcu te- tea teb tec tee ten teo ter tet teu tna tnb tnc tne tnn tno tnr tnt to- toa tob toc toe ton too tor tot tou tra trb trc tre trn tro trr trt tru tta ttb ttc tte ttn tto ttr ttt ttu tua tub tuc tue tun tuo tur tut tuu ua- uaa uab uac uae uan uao uar uat uau uba ubb ubc ube ubn ubo ubr ubt ubu uca ucb ucc uce ucn uco ucr uct ucu uea ueb uec uee uen uer uet un- una unb unc une unn uno unr unt unu uoa uob uoc uoe uon uoo uor uot ur- ura urb urc ure urn uro urr urt uru uta utb utc ute utn uto utr utt utu uua uuc uue uun uur uut uuu