ser ses set sey sla slc sld sle sll slo slp slr sls slt sly soa soc sod soe sol soo sop sor sos sot soy spa spc spd spe spl spo spp spr sps spt spy sr- sra src srd sre srl sro srp srr srs srt sry ss- ssa ssc ssd sse ssl sso ssp ssr sss sst sta stc std ste stl sto stp str sts stt sty sy- sya syc syd sye syl syp syr sys syt taa tac tad tae tal tao tap tar tas tat tay tca tcc tcd tce tcl tco tcp tcr tcs tct tda tdc tdd tde tdl tdo tdp tdr tds tdt tdy te- tea tec ted tee tel teo tep ter tes tet tey tla tlc tld tle tll tlo tlp tlr tls tlt to- toa toc tod toe tol too top tor tos tot toy tpa tpc tpd tpe tpl tpo tpp tpr tps tpt tra trc trd tre trl tro trp trr trs trt try tsa tsc tsd tse tsl tso tsp tsr tss tst tsy tta ttc ttd tte ttl tto ttp ttr tts ttt tty tya tyc tyd tye tyl tyo typ tyr tys tyt yaa yac yad yae yal yao yap yar yas yat yay yca ycc ycd yce ycl yco ycp ycs ycy yda yde ydl ydo yds ydt ydy yea yec yed yee yel yeo yep yer yes yet yey ylc yld yle yll ylr yls ylt yly yoc yod yoe yol yoo yop yor yos yot yoy ypa ypd ypl ypo yps yra yrc yre yro yrp yrs yrt ysa ysc yse ysl yso ysp ysr yss yst ysy yta ytc ytd yte ytl yto ytp ytr yts ytt yyc yye yys yyt yyy