c-- ccc cck ccn cco ccs cct ckc cko cks ckt cn- cnc cnn cno cns cnt co- coc cok con coo cos cot csc csk csn cso css cst ctc ctk ctn cto cts ctt k-t kcc kck kcn kcs kct kkc kkk kkn kks kkt kn- knc knk knn kno knt koc kok kon koo kos kot ksc ksk ksn kso kss kst ktc ktk ktn kto kts ktt ncc nck ncn nco ncs nct nkc nkk nkn nko nks nkt nnc nnk nnn nno nns nnt no- noc nok non noo nos not nsc nsk nsn nso nss nst ntc ntk ntn nto nts ntt oc- occ ock ocn oco ocs oct okc okk oko oks on- onc onk onn ono ons ont oo- ooc ook oon ooo oos oot os- osc osk osn oso oss ost ot- otc otk otn oto ots ott scc sck scn sco scs sct sk- skc skk sko sks skt snc snk snn sno sns snt soc sok son soo sos sot ss- ssc ssk ssn sso sss sst stc stk stn sto sts stt tcc tck tcn tco tcs tct tkc tkk tko tks tkt tnc tnk tnn tno tns tnt to- toc tok ton too tos tot tsc tsk tsn tso tss tst ttc ttk ttn tto tts ttt