rbt re- rea reb ree rei rek ren reo rep rer res ret ria rib rie rii rik rin rio rip rir ris rit rkb rke rkk rko rkp rks rkt rna rnb rni rnn rno rnp rnr rns rnt roa rob roe roi rok ron roo rop ror ros rot rpa rpb rpe rpi rpk rpn rpo rpp rpr rps rpt rra rrb rri rrk rrn rrp rrr rrs rrt rsa rsb rse rsi rsk rsn rso rsp rsr rss rst rta rtb rte rti rtk rtn rto rtp rtr rts rtt saa sab sae sai sak san sao sap sar sas sat sba sbb sbe sbi sbk sbn sbo sbp sbr sbs sbt se- sea seb see sei sek sen seo sep ser ses set sia sib sie sii sik sin sio sip sir sis sit sk- ska skb ske ski skk sko skp skr sks skt sna snb sne sni snk snn sno snp snr sns snt soa sob soe soi sok son soo sop sor sos sot spa spb spe spi spk spn spo spp spr sps spt sr- sra srb sre sri srk srn sro srp srr srs srt ss- ssa ssb sse ssi ssk ssn sso ssp ssr sss sst sta stb ste sti stk stn sto stp str sts stt taa tab tae tai tak tan tao tap tar tas tat tba tbb tbe tbi tbk tbn tbo tbp tbr tbs tbt te- tea teb tee tei tek ten teo tep ter tes tet tia tib tie tii tik tin tio tip tir tis tit tka tkb tke tkk tko tkp tkr tks tkt tna tnb tne tni tnk tnn tno tnp tnr tns tnt to- toa tob toe toi tok ton too top tor tos tot tpa tpb tpe tpi tpk tpn tpo tpp tpr tps tpt tra trb tre tri trk trn tro trp trr trs trt tsa tsb tse tsi tsk tsn tso tsp tsr tss tst tta ttb tte tti ttk ttn tto ttp ttr tts ttt