-er c-- ccc cce ccf ccr cct ce- cec cee cef cer cet cfc cfe cff cfr cft crc cre crf crr crt ctc cte ctf ctr ctt ec- ecc ece ecf ecr ect eec eee eef eer eet ef- efc efe eff efr eft erc ere erf err ert etc ete etf etr ett fcc fce fcf fcr fct fec fee fef fer fet ffc ffe fff ffr fft frc fre frf frr frt ftc fte ftf ftr ftt rcc rce rcf rcr rct re- rec ree ref rer ret rfc rfe rff rfr rft rrc rrf rrr rrt rtc rte rtf rtr rtt tcc tce tcf tcr tct te- tec tee tef ter tet tfc tfe tff tfr tft trc tre trf trr trt ttc tte ttf ttr ttt