c-- ccc cck cco ccs cct ckc cko cks ckt cky co- coc cok coo cos cot coy csc csk cso css cst csy ctc ctk cto cts ctt cty cyc cyk cyo cys cyt k-t kcc kck kcs kct kkc kkk kks kkt kky koc kok koo kos kot koy ksc ksk kso kss kst ktc ktk kto kts ktt kyc kyo kys kyt oc- occ ock oco ocs oct okc okk oko oks oo- ooc ook ooo oos oot os- osc osk oso oss ost ot- otc otk oto ots ott oyo oys scc sck sco scs sct sk- skc skk sko sks skt sky soc sok soo sos sot soy ss- ssc ssk sso sss sst stc stk sto sts stt sty sy- syc syk sys syt tcc tck tco tcs tct tkc tkk tko tks tkt tky to- toc tok too tos tot toy tsc tsk tso tss tst tsy ttc ttk tto tts ttt tty tyc tyo tys tyt ycc yco ycs ycy ykk yoc yok yoo yos yot yoy ysc ysk yso yss yst ysy ytc ytk yto yts ytt yyc yys yyt yyy