-er b-p bbb bbe bbk bbp bbr bbs be- beb bee bek bep ber bes bkb bke bkk bkp bkr bks bpb bpe bpp bpr bps brb bre brk brp brr brs bsb bse bsk bsp bsr bss ebb ebe ebk ebp ebr ebs eeb eee eek eep eer ees ekb eke ekp ekr eks ep- epb epe epp epr eps erb ere erk erp err ers es- esb ese esk esp esr ess kbb kbe kbk kbp kbr kbs ke- keb kee kek kep ker kes kkb kke kkk kkp kkr kks kpe kpk kpp kpr kps krk krp krr krs ksb kse ksk ksp ksr kss p-p pbb pbe pbk pbp pbr pbs peb pee pek pep per pes pkb pke pkp pkr pks ppb ppe ppk ppp ppr pps prb pre prk prp prr prs ps- psb pse psk psp psr pss rbb rbe rbk rbp rbr rbs re- reb ree rek rep rer res rkb rke rkk rkp rks rpb rpe rpk rpp rpr rps rrb rrk rrp rrr rrs rsb rse rsk rsp rsr rss sbb sbe sbk sbp sbr sbs se- seb see sek sep ser ses sk- skb ske skk skp skr sks spb spe spk spp spr sps sr- srb sre srk srp srr srs ss- ssb sse ssk ssp ssr sss