-er b-u bbb bbe bbn bbr bbt bbu be- beb bee ben ber bet beu bnb bne bnn bnr bnt bnu brb bre brn brr brt bru btb bte btn btr btt btu bub bue bun bur but buu ebb ebe ebn ebr ebt ebu eeb eee een eer eet en- enb ene enn enr ent enu erb ere ern err ert eru etb ete etn etr ett etu eu- eub eue eun eur eut nbb nbe nbn nbr nbt nbu ne- neb nee nen ner net neu nnb nne nnn nnt nnu nrb nre nrn nrr nrt nru ntb nte ntn ntr ntt ntu nub nue nun nur nut nuu rbb rbe rbn rbr rbt rbu re- reb ree ren rer ret reu rnb rnn rnr rnt rnu rrb rrn rrr rrt rru rtb rte rtn rtr rtt rtu rub rue run rur rut ruu tbb tbe tbn tbr tbt tbu te- teb tee ten ter tet teu tnb tne tnn tnr tnt trb tre trn trr trt tru ttb tte ttn ttr ttt ttu tub tue tun tur tut tuu ubb ube ubn ubr ubt ubu ueb uee uen uer uet un- unb une unn unr unt unu ur- urb ure urn urr urt uru utb ute utn utr utt utu uue uun uur uut uuu