-er b-p bbb bbe bbg bbo bbp bbr be- beb bee beg beo bep ber bgb bge bgg bgo bgp bgr bob boe bog boo bop bor bpb bpe bpg bpo bpp bpr brb bre brg bro brp brr ebb ebe ebg ebo ebp ebr eeb eee eeg eeo eep eer egb ege egg ego egp egr eo- eob eoe eog eoo eop eor ep- epb epe epg epo epp epr erb ere erg ero erp err g-p gbe gbg gbo gbp gbr ge- geb gee geg geo gep ger ggb ggg ggo ggp ggr gob goe gog goo gop gor gpb gpe gpg gpo gpp gpr grb gre grg gro grp grr ob- obb obe obg obo obp obr oeb oee oeg oeo oep oer oge ogg ogo ogp oo- oob oog ooo oop oor op- opb ope opg opo opp opr or- orb ore org oro orp orr p-p pbb pbe pbg pbo pbp pbr peb pee peg peo pep per pgb pge pgg pgo pgp pgr pob poe pog poo pop por ppb ppe ppg ppo ppp ppr prb pre prg pro prp prr rbb rbe rbg rbo rbp rbr re- reb ree reg reo rep rer rgb rge rgg rgo rgp rgr rob roe rog roo rop ror rpb rpe rpg rpo rpp rpr rrb rrg rrp rrr