-er -up b-p b-u bbb bbc bbe bbp bbr bbt bbu bcb bcc bce bcp bcr bct bcu be- beb bec bee bep ber bet beu bpb bpc bpe bpp bpr bpt bpu brb bre brp brr brt bru btb btc bte btp btr btt btu bub buc bue bup bur but buu c-- cbb cbc cbe cbp cbr cbt cbu ccb ccc cce ccp ccr cct ccu ce- ceb cec cee cep cer cet ceu cpb cpc cpe cpp cpr cpt cpu crb crc cre crp crr crt cru ctb ctc cte ctp ctr ctt ctu cub cuc cue cup cur cut cuu ebb ebc ebe ebp ebr ebt ebu ec- ecb ecc ece ecr ect ecu eeb eec eee eep eer eet ep- epb epc epe epp epr ept epu erb erc ere erp err ert eru etb etc ete etp etr ett etu eu- eub euc eue eup eur eut p-p pbb pbc pbe pbp pbr pbt pbu pcb pcc pce pcp pcr pct pcu peb pec pee pep per pet peu ppb ppc ppe ppp ppr ppt ppu prb prc pre prp prr prt pru pt- ptb ptc pte ptp ptr ptt ptu pub puc pue pup pur put puu rbb rbc rbe rbp rbr rbt rbu rcb rcc rce rcp rcr rct rcu re- reb rec ree rep rer ret reu rpb rpc rpe rpp rpr rpt rpu rrb rrc rrp rrr rrt rru rtb rtc rte rtp rtr rtt rtu rub ruc rue rup rur rut ruu tbb tbc tbe tbp tbr tbt tbu tcb tcc tce tcp tcr tct tcu te- teb tec tee tep ter tet teu tpb tpc tpe tpp tpr tpt tpu trb trc tre trp trr trt tru ttb ttc tte ttp ttr ttt ttu tub tuc tue tup tur tut tuu ubb ubc ube ubp ubr ubt ubu ucb ucc uce ucp ucr uct ucu ueb uec uee uep uer uet up- upb upc upe upp upr upt upu ur- urb urc ure urp urr urt uru utb utc ute utp utr utt utu uuc uue uur uut uuu