c-- ccc ccd ccn cco ccs cct cdc cdd cdn cdo cds cdt cn- cnc cnd cnn cno cns cnt co- coc cod con coo cos cot csc csd csn cso css cst ctc ctd ctn cto cts ctt dcc dcd dcn dco dcs dct ddc ddd ddn ddo dds ddt dnc dnd dnn dno dns dnt doc dod don doo dos dot dsc dsd dsn dso dss dst dtc dtd dtn dto dts dtt ncc ncd ncn nco ncs nct ndc ndd ndn ndo nds ndt nnc nnn nno nns nnt no- noc nod non noo nos not nsc nsd nsn nso nss nst ntc ntd ntn nto nts ntt oc- occ ocd ocn oco ocs oct odc odd odn odo ods odt on- onc ond onn ono ons ont oo- ooc ood oon ooo oos oot os- osc osd osn oso oss ost ot- otc otd otn oto ots ott scc scd scn sco scs sct sdc sdd sdn sdo sds sdt snc snd snn sno sns snt soc sod son soo sos sot ss- ssc ssd ssn sso sss sst stc std stn sto sts stt tcc tcd tcn tco tcs tct tdc tdd tdn tdo tds tdt tnc tnd tnn tno tns tnt to- toc tod ton too tos tot tsc tsd tsn tso tss tst ttc ttd ttn tto tts ttt