-er c-- ccc cce cck ccn cco ccr cct ce- cec cee cek cen ceo cer cet ckc cko ckt cn- cnc cne cnn cno cnr cnt co- coc coe cok con coo cor cot crc cre crk crn cro crr crt ctc cte ctk ctn cto ctr ctt ec- ecc ece eck ecn eco ecr ect eec eee eek een eeo eer eet ekc eke eko ekr ekt en- enc ene enk enn eno enr ent eo- eoc eoe eok eon eoo eor eot erc ere erk ern ero err ert etc ete etk etn eto etr ett k-t kcc kce kck kcn kcr kct ke- kec kee kek ken keo ker ket kkc kke kkk kkn kkr kkt kn- knc kne knk knn kno knr knt koc koe kok kon koo kor kot krc krk krn kro krr krt ktc kte ktk ktn kto ktr ktt ncc nce nck ncn nco ncr nct ne- nec nee nek nen neo ner net nkc nke nkk nkn nko nkr nkt nnc nne nnk nnn nno nnt no- noc noe nok non noo nor not nrc nre nrk nrn nro nrr nrt ntc nte ntk ntn nto ntr ntt oc- occ ock ocn oco ocr oct oec oee oen oeo oer oet okc oke okk oko okr on- onc one onk onn ono onr ont oo- ooc ook oon ooo oor oot or- orc ore ork orn oro orr ort ot- otc ote otk otn oto otr ott rcc rce rcn rco rcr rct re- rec ree rek ren reo rer ret rkc rke rkk rko rkt rnc rnn rno rnr rnt roc roe rok ron roo ror rot rrc rrk rrn rrr rrt rtc rte rtk rtn rto rtr rtt tcc tce tck tcn tco tcr tct te- tec tee tek ten teo ter tet tkc tke tkk tko tkr tkt tnc tne tnk tnn tno tnr tnt to- toc toe tok ton too tor tot trc tre trk trn tro trr trt ttc tte ttk ttn tto ttr ttt