-er c-- ccc cce ccl ccr ccx ce- cec cee cel cer cex cl- clc cle cll clr clx crc cre crl crr crx cxc cxl cxr cxx ec- ecc ece ecl ecr ecx eec eee eel eer eex elc ele ell elr elx erc ere erl err ex- exc exe exl exr exx lcc lce lcl lcr lcx lec lee lel ler lex llc lle lll llr lrc lrr lxc lxr lxx rcc rce rcl rcr rcx re- rec ree rel rer rex rlc rle rll rlr rrc rrl rrr rxr xcl xcr xcx xee xel xer xex xlr xrc xrx xxl xxx