ptt ra- raa rab rac rad rae ral rao rap rar ras rat rba rbb rbc rbd rbe rbl rbo rbp rbr rbs rbt rca rcb rcc rcd rce rcl rco rcp rcr rcs rct rda rdb rdc rdd rde rdl rdo rdp rdr rds rdt re- rea reb rec red ree rel reo rep rer res ret rla rlc rld rle rll rlo rlp rlr rls rlt roa rob roc rod roe rol roo rop ror ros rot rpa rpb rpc rpd rpe rpl rpo rpp rpr rps rpt rra rrb rrc rrd rrl rrp rrr rrs rrt rsa rsb rsc rsd rse rsl rso rsp rsr rss rst rta rtb rtc rtd rte rtl rto rtp rtr rts rtt saa sab sac sad sae sal sao sap sar sas sat sba sbb sbc sbd sbe sbl sbo sbp sbr sbs sbt sca scb scc scd sce scl sco scp scr scs sct sda sdb sdc sdd sde sdl sdo sdp sdr sds sdt se- sea seb sec sed see sel seo sep ser ses set sla slb slc sld sle sll slo slp slr sls slt soa sob soc sod soe sol soo sop sor sos sot spa spb spc spd spe spl spo spp spr sps spt sr- sra srb src srd sre srl sro srp srr srs srt ss- ssa ssb ssc ssd sse ssl sso ssp ssr sss sst sta stb stc std ste stl sto stp str sts stt taa tab tac tad tae tal tao tap tar tas tat tba tbb tbc tbd tbe tbl tbo tbp tbr tbs tbt tca tcb tcc tcd tce tcl tco tcp tcr tcs tct tda tdb tdc tdd tde tdl tdo tdp tdr tds tdt te- tea teb tec ted tee tel teo tep ter tes tet tla tlc tld tle tll tlo tlp tlr tls tlt to- toa tob toc tod toe tol too top tor tos tot tpa tpb tpc tpd tpe tpl tpo tpp tpr tps tpt tra trb trc trd tre trl tro trp trr trs trt tsa tsb tsc tsd tse tsl tso tsp tsr tss tst tta ttb ttc ttd tte ttl tto ttp ttr tts ttt