-er c-- ccc cce ccf ccl ccr ce- cec cee cef cel cer cfc cfe cff cfl cfr cl- clc cle clf cll clr crc cre crf crl crr ec- ecc ece ecf ecl ecr eec eee eef eel eer ef- efc efe eff efl efr elc ele elf ell elr erc ere erf erl err fcc fce fcf fcl fcr fec fee fef fel fer ffc ffe fff ffl ffr flc fle flf fll flr frc fre frf frl frr lcc lce lcf lcl lcr lec lee lef lel ler lfc lfe lff lfl lfr llc lle llf lll llr lrc lrf lrr rcc rce rcf rcl rcr re- rec ree ref rel rer rfc rfe rff rfl rfr rlc rle rlf rll rlr rrc rrf rrl rrr