-er c-- ccc cce ccn cco ccr cct ce- cec cee cen ceo cer cet cn- cnc cne cnn cno cnr cnt co- coc coe con coo cor cot crc cre crn cro crr crt ctc cte ctn cto ctr ctt ec- ecc ece ecn eco ecr ect eec eee een eeo eer eet en- enc ene enn eno enr ent eo- eoc eoe eon eoo eor eot erc ere ern ero err ert etc ete etn eto etr ett ncc nce ncn nco ncr nct ne- nec nee nen neo ner net nnc nne nnn nno nnt no- noc noe non noo nor not nrc nre nrn nro nrr nrt ntc nte ntn nto ntr ntt oc- occ ocn oco ocr oct oec oee oen oeo oer oet on- onc one onn ono onr ont oo- ooc oon ooo oor oot or- orc ore orn oro orr ort ot- otc ote otn oto otr ott rcc rce rcn rco rcr rct re- rec ree ren reo rer ret rnc rnn rno rnr rnt roc roe ron roo ror rot rrc rrn rrr rrt rtc rte rtn rto rtr rtt tcc tce tcn tco tcr tct te- tec tee ten teo ter tet tnc tne tnn tno tnr tnt to- toc toe ton too tor tot trc tre trn tro trr trt ttc tte ttn tto ttr ttt