-er a-a a-c aaa aac aad aae aar aas ac- aca acc acd ace acr acs ad- ada adc add ade adr ads aea aec aed aee aer aes ar- ara arc ard are arr ars as- asa asc asd ase asr ass c-- caa cac cad cae car cas cca ccc ccd cce ccr ccs cda cdc cdd cde cdr cds ce- cea cec ced cee cer ces cra crc crd cre crr crs csa csc csd cse csr css daa dac dad dae dar das dca dcc dcd dce dcr dcs dda ddc ddd dde ddr dds de- dea dec ded dee der des dra drc drd dre drr drs dsa dsc dsd dse dsr dss eaa eac ead eae ear eas ec- eca ecc ecd ece ecr ecs ed- eda edc edd ede edr eds eea eec eed eee eer ees era erc erd ere err ers es- esa esc esd ese esr ess ra- raa rac rad rae rar ras rca rcc rcd rce rcr rcs rda rdc rdd rde rdr rds re- rea rec red ree rer res rra rrc rrd rrr rrs rsa rsc rsd rse rsr rss saa sac sad sae sar sas sca scc scd sce scr scs sda sdc sdd sde sdr sds se- sea sec sed see ser ses sr- sra src srd sre srr srs ss- ssa ssc ssd sse ssr sss