c-- ccc cce cco ccs cct ccx ce- cec cee ceo ces cet cex co- coc coe coo cos cot cox csc cse cso css cst csx ctc cte cto cts ctt ctx cxc cxo cxs cxt cxx ec- ecc ece eco ecs ect ecx eec eee eeo ees eet eex eo- eoc eoe eoo eos eot es- esc ese eso ess est esx etc ete eto ets ett etx ex- exc exe exo exs ext exx oc- occ oco ocs oct ocx oec oee oeo oes oet oex oo- ooc ooo oos oot oox os- osc ose oso oss ost osx ot- otc ote oto ots ott ox- oxc oxo oxt oxx scc sce sco scs sct scx se- sec see seo ses set sex soc soe soo sos sot sox ss- ssc sse sso sss sst ssx stc ste sto sts stt stx sxc sxs sxt t-x tcc tce tco tcs tct tcx te- tec tee teo tes tet tex to- toc toe too tos tot tox tsc tse tso tss tst tsx ttc tte tto tts ttt ttx txe txs txt xcx xee xes xet xex xoc xoo xos xot xox xsc xss xst xtc xts xtx xxo xxx