-er b-p bbb bbe bbg bbp bbr bbs be- beb bee beg bep ber bes bgb bge bgg bgp bgr bgs bpb bpe bpg bpp bpr bps brb bre brg brp brr brs bsb bse bsg bsp bsr bss ebb ebe ebg ebp ebr ebs eeb eee eeg eep eer ees egb ege egg egp egr egs ep- epb epe epg epp epr eps erb ere erg erp err ers es- esb ese esg esp esr ess g-p gbe gbg gbp gbr gbs ge- geb gee geg gep ger ges ggb ggg ggp ggr ggs gpb gpe gpg gpp gpr gps grb gre grg grp grr grs gsb gse gsg gsp gsr gss p-p pbb pbe pbg pbp pbr pbs peb pee peg pep per pes pgb pge pgg pgp pgr pgs ppb ppe ppg ppp ppr pps prb pre prg prp prr prs ps- psb pse psg psp psr pss rbb rbe rbg rbp rbr rbs re- reb ree reg rep rer res rgb rge rgg rgp rgr rgs rpb rpe rpg rpp rpr rps rrb rrg rrp rrr rrs rsb rse rsg rsp rsr rss sbb sbe sbg sbp sbr sbs se- seb see seg sep ser ses sgb sge sgg sgp sgr sgs spb spe spg spp spr sps sr- srb sre srg srp srr srs ss- ssb sse ssg ssp ssr sss