ots ott ra- raa rac rad rae raf rai ral rao rar ras rat rca rcc rcd rce rcf rci rcl rco rcr rcs rct rda rdc rdd rde rdf rdi rdl rdo rdr rds rdt re- rea rec red ree ref rei rel reo rer res ret rfa rfc rfd rfe rff rfi rfl rfo rfr rfs rft ria ric rid rie rif rii ril rio rir ris rit rla rlc rld rle rlf rli rll rlo rlr rls rlt roa roc rod roe rof roi rol roo ror ros rot rra rrc rrd rrf rri rrl rrr rrs rrt rsa rsc rsd rse rsf rsi rsl rso rsr rss rst rta rtc rtd rte rtf rti rtl rto rtr rts rtt saa sac sad sae saf sai sal sao sar sas sat sca scc scd sce scf sci scl sco scr scs sct sda sdc sdd sde sdf sdi sdl sdo sdr sds sdt se- sea sec sed see sef sei sel seo ser ses set sfa sfc sfd sfe sff sfi sfl sfo sfr sfs sft sia sic sid sie sif sii sil sio sir sis sit sla slc sld sle slf sli sll slo slr sls slt soa soc sod soe sof soi sol soo sor sos sot sr- sra src srd sre srf sri srl sro srr srs srt ss- ssa ssc ssd sse ssf ssi ssl sso ssr sss sst sta stc std ste stf sti stl sto str sts stt taa tac tad tae taf tai tal tao tar tas tat tca tcc tcd tce tcf tci tcl tco tcr tcs tct tda tdc tdd tde tdf tdi tdl tdo tdr tds tdt te- tea tec ted tee tef tei tel teo ter tes tet tfa tfc tfd tfe tff tfi tfl tfo tfr tfs tft tia tic tid tie tif tii til tio tir tis tit tla tlc tld tle tlf tli tll tlo tlr tls tlt to- toa toc tod toe tof toi tol too tor tos tot tra trc trd tre trf tri trl tro trr trs trt tsa tsc tsd tse tsf tsi tsl tso tsr tss tst tta ttc ttd tte ttf tti ttl tto ttr tts ttt