sfr sfs sft sfu slc sle slf sll sln slo slp slr sls slt slu snc sne snf snl snn sno snp snr sns snt snu soc soe sof sol son soo sop sor sos sot sou spc spe spf spl spn spo spp spr sps spt spu sr- src sre srf srl srn sro srp srr srs srt ss- ssc sse ssf ssl ssn sso ssp ssr sss sst ssu stc ste stf stl stn sto stp str sts stt stu suc sue suf sul sun suo sup sur sus sut suu tcc tce tcf tcl tcn tco tcp tcr tcs tct tcu te- tec tee tef tel ten teo tep ter tes tet teu tfc tfe tff tfl tfn tfo tfp tfr tfs tft tfu tlc tle tlf tll tln tlo tlp tlr tls tlt tlu tnc tne tnf tnl tnn tno tnp tnr tns tnt to- toc toe tof tol ton too top tor tos tot tou tpc tpe tpf tpl tpn tpo tpp tpr tps tpt tpu trc tre trf trl trn tro trp trr trs trt tru tsc tse tsf tsl tsn tso tsp tsr tss tst tsu ttc tte ttf ttl ttn tto ttp ttr tts ttt ttu tuc tue tuf tul tun tuo tup tur tus tut tuu ucc uce ucf ucl ucn uco ucp ucr ucs uct ucu uec uee uef uel uen uep uer ues uet ufc ufe uff ufl ufn ufo ufp ufr ufs uft ufu ulc ule ulf ull uln ulo ulp ulr uls ult ulu un- unc une unf unl unn uno unp unr uns unt unu uoc uoe uol uon uoo uop uor uos uot up- upc upe upf upn upo upp upr ups upt upu ur- urc ure urf url urn uro urp urr urs urt uru usc use usf usl usn uso usp usr uss ust usu utc ute utf utl utn uto utp utr uts utt utu uuc uue uun uur uus uut uuu