c-- ccc ccd ccn cco ccr cdc cdd cdn cdo cdr cn- cnc cnd cnn cno cnr co- coc cod con coo cor crc crd crn cro crr dcc dcd dcn dco dcr ddc ddd ddn ddo ddr dnc dnd dnn dno dnr doc dod don doo dor drc drd drn dro drr ncc ncd ncn nco ncr ndc ndd ndn ndo ndr nnc nnn nno no- noc nod non noo nor nrc nrd nrn nro nrr oc- occ ocd ocn oco ocr odc odd odn odo odr on- onc ond onn ono onr oo- ooc ood oon ooo oor or- orc ord orn oro orr rcc rcd rcn rco rcr rdc rdd rdn rdo rdr rnc rnd rnn rno rnr roc rod ron roo ror rrc rrd rrn rrr