-er a-a a-b a-t aaa aab aae aan aar aat aau aax ab- aba abb abe abn abr abt abu abx aea aeb aee aen aer aet aeu aex an- ana anb ane ann anr ant anu anx ar- ara arb are arn arr art aru arx at- ata atb ate atn atr att atu atx au- aua aub aue aun aur aut aux ax- axa axe axn axr axt axx b-u baa bab bae ban bar bat bau bax bba bbb bbe bbn bbr bbt bbu bbx be- bea beb bee ben ber bet beu bex bna bnb bne bnn bnr bnt bnu bnx bra brb bre brn brr brt bru brx bta btb bte btn btr btt btu btx bua bub bue bun bur but buu bux bxb bxn bxx eaa eab eae ean ear eat eau eax eba ebb ebe ebn ebr ebt ebu ebx eea eeb eee een eer eet eex en- ena enb ene enn enr ent enu era erb ere ern err ert eru eta etb ete etn etr ett etu etx eu- eua eub eue eun eur eut eux ex- exa exe exr ext exu exx naa nab nae nan nar nat nau nax nba nbb nbe nbn nbr nbt nbu nbx ne- nea neb nee nen ner net neu nex nna nnb nne nnn nnt nnu nra nrb nre nrn nrr nrt nru nrx nta ntb nte ntn ntr ntt ntu ntx nua nub nue nun nur nut nuu nux nxt ra- raa rab rae ran rar rat rau rax rba rbb rbe rbn rbr rbt rbu rbx re- rea reb ree ren rer ret reu rex rna rnb rnn rnr rnt rnu rra rrb rrn rrr rrt rru rta rtb rte rtn rtr rtt rtu rtx rua rub rue run rur rut ruu rux rxr t-x taa tab tae tan tar tat tau tax tba tbb tbe tbn tbr tbt tbu te- tea teb tee ten ter tet teu tex tna tnb tne tnn tnr tnt tnx tra trb tre trn trr trt tru trx tta ttb tte ttn ttr ttt ttu ttx tua tub tue tun tur tut tuu tux txe txn txt txu ua- uaa uab uae uan uar uat uau uba ubb ube ubn ubr ubt ubu ubx uea ueb uee uen uer uet un- una unb une unn unr unt unu unx ur- ura urb ure urn urr urt uru urx uta utb ute utn utr utt utu utx uua uue uun uur uut uuu uxb uxr uxt uxu xaa xan xar xat xau xbe xbr xbx xee xen xer xet xeu xex xna xnu xrt xrx xtr xtx xue xun xxx