cccc ccee ccrc ccre ccrt cctc cctt cec- cece cect ceec cer- cerc cere cert cet- cete cexe crcc crce crcr cre- crec cree cret crex crrt crtc ctec ctrc cxxx eccc ecce ecct ecrc ecrr ect- ectc eeee eerc eetc eete eext er-x ercc erce erec erer eret errc erre etcc etec etee eter etre ette exec exer exrx exte extr rccc rcet rctc recc rece recr rect reet rere rert rete retr rett rexx rrrr rtcc rtce rtee rtex tccc tctc tecr tect teec teer teet ter- terc tere terr tete tetr tett tetx text trcc tre- trec tree tret trex trtc trte trtr tter tttt txtr xeer xer- xert xexe xxxx