-er eee eek eer ees eet eex eke ekr eks ekt eku ere erk err ers ert eru es- ese esk esr ess est esu esx ete etk etr ets ett etu etx eu- eue eur eus eut eux ex- exe exr exs ext exu exx k-t ke- kee kek ker kes ket kex kke kkk kkr kks kkt kku krk krr krs krt kru kse ksk ksr kss kst ksu kte ktk ktr kts ktt ktu kue kuk kur kus kut kuu re- ree rek rer res ret reu rex rke rkk rks rkt rku rrk rrr rrs rrt rru rse rsk rsr rss rst rsu rsx rte rtk rtr rts rtt rtu rtx rue ruk rur rus rut ruu rux rxr rxs se- see sek ser ses set seu sex sk- ske skk skr sks skt sku skx sr- sre srk srr srs srt srx ss- sse ssk ssr sss sst ssu ssx ste stk str sts stt stu stx sue suk sur sus sut suu sux sxs sxt sxu t-x te- tee tek ter tes tet teu tex tke tkk tkr tks tkt tre trk trr trs trt tru trx tse tsk tsr tss tst tsu tsx tte ttk ttr tts ttt ttu ttx tue tuk tur tus tut tuu tux txe txk txs txt txu uee uer ues uet uke ukk ukr uku ur- ure urk urr urs urt uru urx use usk usr uss ust usu usx ute utk utr uts utt utu utx uue uur uus uut uuu uxr uxt uxu xee xer xes xet xeu xex xke xks xrt xrx xss xst xtr xts xtx xue xus xxx