-er a-a a-b a-c a-t aaa aab aac aae aan aar aat aau aax ab- aba abb abc abe abn abr abt abu abx ac- aca acb acc ace acn acr act acu acx aea aeb aec aee aen aer aet aeu aex an- ana anb anc ane ann anr ant anu anx ar- ara arb arc are arn arr art aru arx at- ata atb atc ate atn atr att atu atx au- aua aub auc aue aun aur aut aux ax- axa axe axn axr axt axx b-u baa bab bac bae ban bar bat bau bax bba bbb bbc bbe bbn bbr bbt bbu bbx bca bcb bcc bce bcn bcr bct bcu bcx be- bea beb bec bee ben ber bet beu bex bna bnb bnc bne bnn bnr bnt bnu bnx bra brb bre brn brr brt bru brx bta btb btc bte btn btr btt btu btx bua bub buc bue bun bur but buu bux bxb bxn bxx c-- caa cab cac cae can car cat cau cax cba cbb cbc cbe cbn cbr cbt cbu cbx cca ccb ccc cce ccn ccr cct ccu ccx ce- cea ceb cec cee cen cer cet ceu cex cn- cna cnb cnc cne cnn cnr cnt cnu cnx cra crb crc cre crn crr crt cru crx cta ctb ctc cte ctn ctr ctt ctu ctx cua cub cuc cue cun cur cut cuu cxc cxr cxt cxx eaa eab eac eae ean ear eat eau eax eba ebb ebc ebe ebn ebr ebt ebu ebx ec- eca ecb ecc ece ecn ecr ect ecu ecx eea eeb eec eee een eer eet eex en- ena enb enc ene enn enr ent enu era erb erc ere ern err ert eru eta etb etc ete etn etr ett etu etx eu- eua eub euc eue eun eur eut eux ex- exa exc exe exr ext exu exx naa nab nac nae nan nar nat nau nax nba nbb nbc nbe nbn nbr nbt nbu nbx nca ncb ncc nce ncn ncr nct ncu ncx ne- nea neb nec nee nen ner net neu nex nna nnb nnc nne nnn nnt nnu nra nrb nrc nre nrn nrr nrt nru nrx nta ntb ntc nte ntn ntr ntt ntu ntx nua nub nuc nue nun nur nut nuu nux nxc nxt ra- raa rab rac rae ran rar rat rau rax rba rbb rbc rbe rbn rbr rbt rbu rbx rca rcb rcc rce rcn rcr rct rcu rcx re- rea reb rec ree ren rer ret reu rex rna rnb rnc rnn rnr rnt rnu rra rrb rrc rrn rrr rrt rru rta rtb rtc rte rtn rtr rtt rtu rtx rua rub ruc rue run rur rut ruu rux rxr t-x taa tab tac tae tan tar tat tau tax tba tbb tbc tbe tbn tbr tbt tbu tca tcb tcc tce tcn tcr tct tcu tcx te- tea teb tec tee ten ter tet teu tex tna tnb tnc tne tnn tnr tnt tnx tra trb trc tre trn trr trt tru trx tta ttb ttc tte ttn ttr ttt ttu ttx tua tub tuc tue tun tur tut tuu tux txe txn txt txu ua- uaa uab uac uae uan uar uat uau uba ubb ubc ube ubn ubr ubt ubu ubx uca ucb ucc uce ucn ucr uct ucu uea ueb uec uee uen uer uet un- una unb unc une unn unr unt unu unx ur- ura urb urc ure urn urr urt uru urx uta utb utc ute utn utr utt utu utx uua uuc uue uun uur uut uuu uxb uxc uxr uxt uxu xaa xac xan xar xat xau xbc xbe xbr xbx xcb xcr xcx xee xen xer xet xeu xex xna xnc xnu xrc xrt xrx xtc xtr xtx xue xun xxx