c-- ccc cck cco ccs cct ckc cko cks ckt co- coc cok coo coq cos cot cqc cqo cqs cqt csc csk cso csq css cst ctc ctk cto ctq cts ctt k-t kcc kck kcs kct kkc kkk kks kkt koc kok koo kos kot ksc ksk kso kss kst ktc ktk kto kts ktt oc- occ ock oco ocs oct okc okk oko oks oo- ooc ook ooo oos oot oqo os- osc osk oso osq oss ost ot- otc otk oto ots ott qcc qco qcs qct qoo qos qqk qqq qsc qso qst qtc qto qtq qts scc sck sco scs sct sk- skc skk sko skq sks skt soc sok soo soq sos sot sqq sqs ss- ssc ssk sso ssq sss sst stc stk sto stq sts stt tcc tck tco tcs tct tkc tkk tko tks tkt to- toc tok too toq tos tot tqo tsc tsk tso tsq tss tst ttc ttk tto tts ttt