-er c-- ccc cce ccm ccr cct ce- cec cee cem cer cet cmc cme cmm cmr cmt crc cre crm crr crt ctc cte ctm ctr ctt ec- ecc ece ecm ecr ect eec eee eem eer eet em- emc eme emm emr emt erc ere erm err ert etc ete etm etr ett m-r mc- mcc mce mcm mcr mct mec mee mem mer met mmc mme mmm mmr mmt mrc mre mrm mrr mrt mtc mte mtm mtr mtt rcc rce rcm rcr rct re- rec ree rem rer ret rmc rme rmm rmr rmt rrc rrm rrr rrt rtc rte rtm rtr rtt tcc tce tcm tcr tct te- tec tee tem ter tet tmc tme tmm tmr tmt trc tre trm trr trt ttc tte ttm ttr ttt