rbo rbr rbs rbt rcb rcc rcd rce rcf rci rcm rco rcr rcs rct rdb rdc rdd rde rdf rdi rdm rdo rdr rds rdt re- reb rec red ree ref rei rem reo rer res ret rfb rfc rfd rfe rff rfi rfm rfo rfr rfs rft rib ric rid rie rif rii rim rio rir ris rit rmb rmc rmd rme rmf rmi rmm rmo rmr rms rmt rob roc rod roe rof roi rom roo ror ros rot rrb rrc rrd rrf rri rrm rrr rrs rrt rsb rsc rsd rse rsf rsi rsm rso rsr rss rst rtb rtc rtd rte rtf rti rtm rto rtr rts rtt sbb sbc sbd sbe sbf sbi sbm sbo sbr sbs sbt scb scc scd sce scf sci scm sco scr scs sct sdb sdc sdd sde sdf sdi sdm sdo sdr sds sdt se- seb sec sed see sef sei sem seo ser ses set sfb sfc sfd sfe sff sfi sfm sfo sfr sfs sft sib sic sid sie sif sii sim sio sir sis sit smb smc smd sme smf smi smm smo smr sms smt sob soc sod soe sof soi som soo sor sos sot sr- srb src srd sre srf sri srm sro srr srs srt ss- ssb ssc ssd sse ssf ssi ssm sso ssr sss sst stb stc std ste stf sti stm sto str sts stt tbb tbc tbd tbe tbf tbi tbm tbo tbr tbs tbt tcb tcc tcd tce tcf tci tcm tco tcr tcs tct tdb tdc tdd tde tdf tdi tdm tdo tdr tds tdt te- teb tec ted tee tef tei tem teo ter tes tet tfb tfc tfd tfe tff tfi tfm tfo tfr tfs tft tib tic tid tie tif tii tim tio tir tis tit tmb tmc tmd tme tmf tmi tmm tmo tmr tms tmt to- tob toc tod toe tof toi tom too tor tos tot trb trc trd tre trf tri trm tro trr trs trt tsb tsc tsd tse tsf tsi tsm tso tsr tss tst ttb ttc ttd tte ttf tti ttm tto ttr tts ttt