c-- ccc ccd ccf cco ccr ccu cdc cdd cdf cdo cdr cdu cfc cfd cff cfo cfr cfu co- coc cod cof coo cor cou crc crd crf cro crr cru cuc cud cuf cuo cur cuu dcc dcd dcf dco dcr dcu ddc ddd ddf ddo ddr ddu dfc dfd dff dfo dfr dfu doc dod dof doo dor dou drc drd dro drr dru duc dud duf duo dur fcc fcd fcf fco fcr fcu fdc fdd fdf fdo fdr fdu ffc ffd fff ffo ffr ffu foc fof foo for fou frc frd frf fro frr fru fud fuf fuo fur fuu oc- occ ocd ocf oco ocr ocu odc odd odf odo odr odu of- ofc ofd off ofo ofr ofu oo- ooc ood oof ooo oor or- orc ord orf oro orr oru ou- ouc oud ouf ouo our rcc rcd rcf rco rcr rcu rdc rdd rdf rdo rdr rdu rfc rfd rff rfo rfr rfu roc rod rof roo ror rou rrc rrd rrf rrr rru ruc rud ruf ruo rur ruu ucc ucd ucf uco ucr ucu udc udd udf udo udr udu ufc ufd uff ufo ufr ufu uoc uod uoo uor ur- urc urd urf uro urr uru uuc uur uuu