-er c-- ccc ccd cce ccr ccu cdc cdd cde cdr cdu ce- cec ced cee cer ceu crc crd cre crr cru cuc cud cue cur cuu dcc dcd dce dcr dcu ddc ddd dde ddr ddu de- dec ded dee der deu drc drd dre drr dru duc dud due dur ec- ecc ecd ece ecr ecu ed- edc edd ede edr edu eec eed eee eer erc erd ere err eru eu- euc eud eue eur rcc rcd rce rcr rcu rdc rdd rde rdr rdu re- rec red ree rer reu rrc rrd rrr rru ruc rud rue rur ruu ucc ucd uce ucr ucu udc udd ude udr udu uec ued uee uer ur- urc urd ure urr uru uuc uue uur uuu