-er c-- ccc cce ccn ccr cct ccv ce- cec cee cen cer cet cev cn- cnc cne cnn cnr cnt cnv crc cre crn crr crt crv ctc cte ctn ctr ctt ctv cvc cve cvn cvr cvt cvv ec- ecc ece ecn ecr ect ecv eec eee een eer eet eev en- enc ene enn enr ent env erc ere ern err ert erv etc ete etn etr ett etv evc eve evn evr evt evv ncc nce ncn ncr nct ncv ne- nec nee nen ner net nev nnc nne nnn nnt nnv nrc nre nrn nrr nrt nrv ntc nte ntn ntr ntt ntv nvc nve nvn nvt nvv rcc rce rcn rcr rct rcv re- rec ree ren rer ret rev rnc rnn rnr rnt rnv rrc rrn rrr rrt rtc rte rtn rtr rtt rtv rvc rve rvn rvr rvt rvv tcc tce tcn tcr tct tcv te- tec tee ten ter tet tev tnc tne tnn tnr tnt trc tre trn trr trt trv ttc tte ttn ttr ttt ttv tvc tve tvn tvr tvt v-e vcc vce vcn vcr vct vec vee ven ver vet vn- vnr vnv vrc vre vrn vrr vrt vtc vte vtr vtt vtv vvc vvr vvt vvv