-er c-- ccc ccd cce cco ccr ccu cdc cdd cde cdo cdr cdu ce- cec ced cee ceo cer ceu co- coc cod coe coo cor cou crc crd cre cro crr cru cuc cud cue cuo cur cuu dcc dcd dce dco dcr dcu ddc ddd dde ddo ddr ddu de- dec ded dee deo der deu doc dod doe doo dor dou drc drd dre dro drr dru duc dud due duo dur ec- ecc ecd ece eco ecr ecu ed- edc edd ede edo edr edu eec eed eee eeo eer eo- eoc eod eoe eoo eor eou erc erd ere ero err eru eu- euc eud eue eur oc- occ ocd oco ocr ocu odc odd ode odo odr odu oec oed oee oeo oer oo- ooc ood ooo oor or- orc ord ore oro orr oru ou- ouc oud oue ouo our rcc rcd rce rco rcr rcu rdc rdd rde rdo rdr rdu re- rec red ree reo rer reu roc rod roe roo ror rou rrc rrd rrr rru ruc rud rue ruo rur ruu ucc ucd uce uco ucr ucu udc udd ude udo udr udu uec ued uee uer uoc uod uoe uoo uor ur- urc urd ure uro urr uru uuc uue uur uuu