-er a-a a-b a-c a-t aaa aab aac aae aar aat aau aav ab- aba abb abc abe abr abt abu abv ac- aca acb acc ace acr act acu acv aea aeb aec aee aer aet aeu aev ar- ara arb arc are arr art aru arv at- ata atb atc ate atr att atu atv au- aua aub auc aue aur aut auv av- ava avb avc ave avr avt avu b-u baa bab bac bae bar bat bau bav bba bbb bbc bbe bbr bbt bbu bca bcb bcc bce bcr bct bcu bcv be- bea beb bec bee ber bet beu bev bra brb bre brr brt bru brv bta btb btc bte btr btt btu btv bua bub buc bue bur but buu bva bvb bvc bve bvr bvt bvu bvv c-- caa cab cac cae car cat cau cav cba cbb cbc cbe cbr cbt cbu cbv cca ccb ccc cce ccr cct ccu ccv ce- cea ceb cec cee cer cet ceu cev cra crb crc cre crr crt cru crv cta ctb ctc cte ctr ctt ctu ctv cua cub cuc cue cur cut cuu cuv cva cvb cvc cve cvr cvt cvu cvv eaa eab eac eae ear eat eau eav eba ebb ebc ebe ebr ebt ebu ebv ec- eca ecb ecc ece ecr ect ecu ecv eea eeb eec eee eer eet eev era erb erc ere err ert eru erv eta etb etc ete etr ett etu etv eu- eua eub euc eue eur eut euv eva evb evc eve evr evt evv ra- raa rab rac rae rar rat rau rav rba rbb rbc rbe rbr rbt rbu rca rcb rcc rce rcr rct rcu rcv re- rea reb rec ree rer ret reu rev rra rrb rrc rrr rrt rru rta rtb rtc rte rtr rtt rtu rtv rua rub ruc rue rur rut ruu ruv rva rvb rvc rve rvr rvt rvu rvv taa tab tac tae tar tat tau tav tba tbb tbc tbe tbr tbt tbu tbv tca tcb tcc tce tcr tct tcu tcv te- tea teb tec tee ter tet teu tev tra trb trc tre trr trt tru trv tta ttb ttc tte ttr ttt ttu ttv tua tub tuc tue tur tut tuu tuv tva tvb tvc tve tvr tvt tvu ua- uaa uab uac uae uar uat uau uav uba ubb ubc ube ubr ubt ubu ubv uca ucb ucc uce ucr uct ucu ucv uea ueb uec uee uer uet ur- ura urb urc ure urr urt uru uta utb utc ute utr utt utu utv uua uuc uue uur uut uuu uva uvb uvc uve uvu uvv v-a v-e vaa vab vac vae var vat vau vav vba vbc vbr vbv vca vcc vce vcr vct vcu vea veb vec vee ver vet veu vra vrb vrc vre vrr vrt vru vta vtb vtc vte vtr vtt vtu vtv vue vur vut vuv vva vvb vvc vvr vvt vvv