-er -up b-p b-u bbb bbc bbe bbo bbp bbr bbu bcb bcc bce bco bcp bcr bcu be- beb bec bee beo bep ber beu bob boc boe boo bop bor bou bpb bpc bpe bpo bpp bpr bpu brb bre bro brp brr bru bub buc bue buo bup bur buu c-- cbb cbc cbe cbo cbp cbr cbu ccb ccc cce cco ccp ccr ccu ce- ceb cec cee ceo cep cer ceu co- cob coc coe coo cop cor cou cpb cpc cpe cpo cpp cpr cpu crb crc cre cro crp crr cru cub cuc cue cuo cup cur cuu ebb ebc ebe ebo ebp ebr ebu ec- ecb ecc ece eco ecr ecu eeb eec eee eeo eep eer eo- eob eoc eoe eoo eop eor eou ep- epb epc epe epo epp epr epu erb erc ere ero erp err eru eu- eub euc eue eup eur ob- obb obc obe obo obp obr obu oc- ocb occ oco ocp ocr ocu oeb oec oee oeo oep oer oo- oob ooc ooo oop oor op- opb opc ope opo opp opr or- orb orc ore oro orp orr oru ou- ouc oue ouo oup our p-p pbb pbc pbe pbo pbp pbr pbu pcb pcc pce pco pcp pcr pcu peb pec pee peo pep per peu pob poc poe poo pop por pou ppb ppc ppe ppo ppp ppr ppu prb prc pre pro prp prr pru pub puc pue pup pur puu rbb rbc rbe rbo rbp rbr rbu rcb rcc rce rco rcp rcr rcu re- reb rec ree reo rep rer reu rob roc roe roo rop ror rou rpb rpc rpe rpo rpp rpr rpu rrb rrc rrp rrr rru rub ruc rue ruo rup rur ruu ubb ubc ube ubo ubp ubr ubu ucb ucc uce uco ucp ucr ucu ueb uec uee uep uer uob uoc uoe uoo uop uor up- upb upc upe upo upp upr upu ur- urb urc ure uro urp urr uru uuc uue uur uuu