-er -up b-p b-u bbb bbe bbf bbo bbp bbr bbu be- beb bee bef beo bep ber beu bfb bfe bff bfo bfp bfr bfu bob boe bof boo bop bor bou bpb bpe bpf bpo bpp bpr bpu brb bre brf bro brp brr bru bub bue buf buo bup bur buu ebb ebe ebf ebo ebp ebr ebu eeb eee eef eeo eep eer ef- efb efe eff efo efp efr eo- eob eoe eof eoo eop eor eou ep- epb epe epf epo epp epr epu erb ere erf ero erp err eru eu- eub eue euf eup eur fbb fbe fbf fbo fbp fbr fbu feb fee fef feo fep fer feu ffe fff ffo ffp ffr ffu fob foe fof foo fop for fou fpb fpe fpo fpp fpr fpu frb fre frf fro frp frr fru fub fue fuf fuo fup fur fuu ob- obb obe obf obo obp obr obu oeb oee oef oeo oep oer of- ofb ofe off ofo ofp ofr ofu oo- oob oof ooo oop oor op- opb ope opf opo opp opr or- orb ore orf oro orp orr oru ou- oue ouf ouo oup our p-p pbb pbe pbf pbo pbp pbr pbu peb pee pef peo pep per peu pfb pfe pff pfo pfp pfr pfu pob poe pof poo pop por pou ppb ppe ppf ppo ppp ppr ppu prb pre prf pro prp prr pru pub pue puf pup pur puu rbb rbe rbf rbo rbp rbr rbu re- reb ree ref reo rep rer reu rfb rfe rff rfo rfp rfr rfu rob roe rof roo rop ror rou rpb rpe rpf rpo rpp rpr rpu rrb rrf rrp rrr rru rub rue ruf ruo rup rur ruu ubb ube ubf ubo ubp ubr ubu ueb uee uef uep uer ufe uff ufo ufp ufr ufu uob uoe uoo uop uor up- upb upe upf upo upp upr upu ur- urb ure urf uro urp urr uru uue uur uuu