-er a-a a-b a-t a-z aaa aab aae aar aat aau aaz ab- aba abb abe abr abt abu abz aea aeb aee aer aet aeu aez ar- ara arb are arr art aru arz at- ata atb ate atr att atu atz au- aua aub aue aur aut auz az- aza azb aze azt azu azz b-u baa bab bae bar bat bau baz bba bbb bbe bbr bbt bbu be- bea beb bee ber bet beu bez bra brb bre brr brt bru brz bta btb bte btr btt btu btz bua bub bue bur but buu buz bza bze bzr bzu bzz eaa eab eae ear eat eau eaz eba ebb ebe ebr ebt ebu eea eeb eee eer eet era erb ere err ert eru erz eta etb ete etr ett etu etz eu- eua eub eue eur eut eze ezr ezz ra- raa rab rae rar rat rau raz rba rbb rbe rbr rbt rbu re- rea reb ree rer ret reu rez rra rrb rrr rrt rru rta rtb rte rtr rtt rtu rtz rua rub rue rur rut ruu ruz rza rzb rze taa tab tae tar tat tau taz tba tbb tbe tbr tbt tbu tbz te- tea teb tee ter tet teu tez tra trb tre trr trt tru trz tta ttb tte ttr ttt ttu tua tub tue tur tut tuu tuz tza tze tzu ua- uaa uab uae uar uat uau uaz uba ubb ube ubr ubt ubu uea ueb uee uer uet ur- ura urb ure urr urt uru urz uta utb ute utr utt utu utz uua uue uur uut uuu uza uzb uzu zaa zab zar zat zaz zbb zbr zbt zea zeb zee zer zet zez zta zte ztr zub zur zut zuz zzr zzt zzz