sfe sff sfi sfn sfo sfp sfr sfs sft sfu sic sie sif sii sin sio sip sir sis sit siu snc sne snf sni snn sno snp snr sns snt snu soc soe sof soi son soo sop sor sos sot sou spc spe spf spi spn spo spp spr sps spt spu sr- src sre srf sri srn sro srp srr srs srt ss- ssc sse ssf ssi ssn sso ssp ssr sss sst ssu stc ste stf sti stn sto stp str sts stt stu suc sue suf sui sun suo sup sur sus sut suu tcc tce tcf tci tcn tco tcp tcr tcs tct tcu te- tec tee tef tei ten teo tep ter tes tet teu tfc tfe tff tfi tfn tfo tfp tfr tfs tft tfu tic tie tif tii tin tio tip tir tis tit tiu tnc tne tnf tni tnn tno tnp tnr tns tnt to- toc toe tof toi ton too top tor tos tot tou tpc tpe tpf tpi tpn tpo tpp tpr tps tpt tpu trc tre trf tri trn tro trp trr trs trt tru tsc tse tsf tsi tsn tso tsp tsr tss tst tsu ttc tte ttf tti ttn tto ttp ttr tts ttt ttu tuc tue tuf tui tun tuo tup tur tus tut tuu ucc uce ucf uci ucn uco ucp ucr ucs uct ucu uec uee uef uei uen uep uer ues uet ufc ufe uff ufi ufn ufo ufp ufr ufs uft ufu uic uie uif uii uin uio uip uir uis uit uiu un- unc une unf uni unn uno unp unr uns unt unu uoc uoe uon uoo uop uor uos uot up- upc upe upf upi upn upo upp upr ups upt upu ur- urc ure urf uri urn uro urp urr urs urt uru usc use usf usi usn uso usp usr uss ust usu utc ute utf uti utn uto utp utr uts utt utu uuc uue uun uur uus uut uuu