-er b-u bbb bbc bbe bbn bbr bbt bbu bcb bcc bce bcn bcr bct bcu be- beb bec bee ben ber bet beu bnb bnc bne bnn bnr bnt bnu brb bre brn brr brt bru btb btc bte btn btr btt btu bub buc bue bun bur but buu c-- cbb cbc cbe cbn cbr cbt cbu ccb ccc cce ccn ccr cct ccu ce- ceb cec cee cen cer cet ceu cn- cnb cnc cne cnn cnr cnt cnu crb crc cre crn crr crt cru ctb ctc cte ctn ctr ctt ctu cub cuc cue cun cur cut cuu ebb ebc ebe ebn ebr ebt ebu ec- ecb ecc ece ecn ecr ect ecu eeb eec eee een eer eet en- enb enc ene enn enr ent enu erb erc ere ern err ert eru etb etc ete etn etr ett etu eu- eub euc eue eun eur eut nbb nbc nbe nbn nbr nbt nbu ncb ncc nce ncn ncr nct ncu ne- neb nec nee nen ner net neu nnb nnc nne nnn nnt nnu nrb nrc nre nrn nrr nrt nru ntb ntc nte ntn ntr ntt ntu nub nuc nue nun nur nut nuu rbb rbc rbe rbn rbr rbt rbu rcb rcc rce rcn rcr rct rcu re- reb rec ree ren rer ret reu rnb rnc rnn rnr rnt rnu rrb rrc rrn rrr rrt rru rtb rtc rte rtn rtr rtt rtu rub ruc rue run rur rut ruu tbb tbc tbe tbn tbr tbt tbu tcb tcc tce tcn tcr tct tcu te- teb tec tee ten ter tet teu tnb tnc tne tnn tnr tnt trb trc tre trn trr trt tru ttb ttc tte ttn ttr ttt ttu tub tuc tue tun tur tut tuu ubb ubc ube ubn ubr ubt ubu ucb ucc uce ucn ucr uct ucu ueb uec uee uen uer uet un- unb unc une unn unr unt unu ur- urb urc ure urn urr urt uru utb utc ute utn utr utt utu uuc uue uun uur uut uuu