c-- ccc ccd cck cco ccs cct cdc cdd cdk cdo cds cdt ckc ckd cko cks ckt co- coc cod cok coo cos cot csc csd csk cso css cst ctc ctd ctk cto cts ctt dcc dcd dck dco dcs dct ddc ddd ddk ddo dds ddt dkc dkk dko dks dkt doc dod dok doo dos dot dsc dsd dsk dso dss dst dtc dtd dtk dto dts dtt k-t kcc kcd kck kcs kct kdc kdk kdo kds kdt kkc kkk kks kkt koc kod kok koo kos kot ksc ksd ksk kso kss kst ktc ktk kto kts ktt oc- occ ocd ock oco ocs oct odc odd odo ods odt okc okd okk oko oks oo- ooc ood ook ooo oos oot os- osc osd osk oso oss ost ot- otc otd otk oto ots ott scc scd sck sco scs sct sdc sdd sdk sdo sds sdt sk- skc skd skk sko sks skt soc sod sok soo sos sot ss- ssc ssd ssk sso sss sst stc std stk sto sts stt tcc tcd tck tco tcs tct tdc tdd tdk tdo tds tdt tkc tkk tko tks tkt to- toc tod tok too tos tot tsc tsd tsk tso tss tst ttc ttd ttk tto tts ttt