c-- ccc ccd ccr ccs ccu cdc cdd cdr cds cdu crc crd crr crs cru csc csd csr css csu cuc cud cur cus cuu dcc dcd dcr dcs dcu ddc ddd ddr dds ddu drc drd drr drs dru dsc dsd dsr dss dsu duc dud dur dus rcc rcd rcr rcs rcu rdc rdd rdr rds rdu rrc rrd rrr rrs rru rsc rsd rsr rss rsu ruc rud rur rus ruu scc scd scr scs scu sdc sdd sdr sds sdu sr- src srd srr srs ss- ssc ssd ssr sss ssu suc sud sur sus suu ucc ucd ucr ucs ucu udc udd udr uds udu ur- urc urd urr urs uru usc usd usr uss usu uuc uur uus uuu