-er c-- ccc ccd cce ccl ccr ccs cdc cdd cde cdl cdr cds ce- cec ced cee cel cer ces cl- clc cld cle cll clr cls crc crd cre crl crr crs csc csd cse csl csr css dcc dcd dce dcl dcr dcs ddc ddd dde ddl ddr dds de- dec ded dee del der des dl- dlc dld dle dll dlr dls drc drd dre drl drr drs dsc dsd dse dsl dsr dss ec- ecc ecd ece ecl ecr ecs ed- edc edd ede edl edr eds eec eed eee eel eer ees elc eld ele ell elr els erc erd ere erl err ers es- esc esd ese esl esr ess lcc lcd lce lcl lcr lcs ldc ldd lde ldl ldr lds lec led lee lel ler les llc lld lle lll llr lls lrc lrd lrr lrs lsc lsd lse lsl lsr lss rcc rcd rce rcl rcr rcs rdc rdd rde rdl rdr rds re- rec red ree rel rer res rlc rld rle rll rlr rls rrc rrd rrl rrr rrs rsc rsd rse rsl rsr rss scc scd sce scl scr scs sdc sdd sde sdl sdr sds se- sec sed see sel ser ses slc sld sle sll slr sls sr- src srd sre srl srr srs ss- ssc ssd sse ssl ssr sss