-er eee eer ees eet eev eex ere err ers ert erv es- ese esr ess est esv esx ete etr ets ett etv etx eve evr evs evt evv ex- exe exr exs ext exx re- ree rer res ret rev rex rrr rrs rrt rse rsr rss rst rsv rsx rte rtr rts rtt rtv rtx rve rvr rvs rvt rvv rxr rxs se- see ser ses set sev sex sr- sre srr srs srt srv srx ss- sse ssr sss sst ssv ssx ste str sts stt stv stx sve svr svs svt svv svx sxs sxt t-x te- tee ter tes tet tev tex tre trr trs trt trv trx tse tsr tss tst tsv tsx tte ttr tts ttt ttv ttx tve tvr tvs tvt tvx txe txs txt v-e vee ver ves vet vex vre vrr vrs vrt vse vsr vss vst vsv vte vtr vts vtt vtv vtx vvr vvs vvt vvv vxr vxs vxv xee xer xes xet xev xex xrt xrx xss xst xtr xts xtv xtx xvt xxv xxx