-er -ic c-- ccc ccd cce cci ccr ccs cdc cdd cde cdi cdr cds ce- cec ced cee cei cer ces ci- cic cid cie cii cir cis crc crd cre cri crr crs csc csd cse csi csr css dcc dcd dce dci dcr dcs ddc ddd dde ddi ddr dds de- dec ded dee dei der des di- dic did die dii dir dis drc drd dre dri drr drs dsc dsd dse dsi dsr dss ec- ecc ecd ece eci ecr ecs ed- edc edd ede edi edr eds eec eed eee eer ees eic eid eie eii eir eis erc erd ere eri err ers es- esc esd ese esi esr ess i-d icc icd ice ici icr ics idc idd ide idi idr ids ie- iec ied iee iei ier ies iic iid iie iii iir iis ir- irc ird ire iri irr irs is- isc isd ise isi isr iss rcc rcd rce rci rcr rcs rdc rdd rde rdi rdr rds re- rec red ree rei rer res ric rid rie rii rir ris rrc rrd rri rrr rrs rsc rsd rse rsi rsr rss scc scd sce sci scr scs sdc sdd sde sdi sdr sds se- sec sed see sei ser ses sic sid sie sii sir sis sr- src srd sre sri srr srs ss- ssc ssd sse ssi ssr sss