c-- ccc cck cco ccp ccr cct ckc cko ckt co- coc cok coo cop cor cot cpc cpk cpo cpp cpr cpt crc crk cro crp crr crt ctc ctk cto ctp ctr ctt k-t kcc kck kcp kcr kct kkc kkk kkp kkr kkt koc kok koo kop kor kot kpc kpk kpo kpp kpr kpt krc krk kro krp krr krt ktc ktk kto ktp ktr ktt oc- occ ock oco ocp ocr oct okc okk oko okp okr oo- ooc ook ooo oop oor oot op- opc opk opo opp opr opt or- orc ork oro orp orr ort ot- otc otk oto otp otr ott p-p pcc pck pco pcp pcr pct pkc pko pkp pkr pkt poc pok poo pop por pot ppc ppk ppo ppp ppr ppt prc prk pro prp prr prt pt- ptc ptk pto ptp ptr ptt rcc rco rcp rcr rct rkc rkk rko rkp rkt roc rok roo rop ror rot rpc rpk rpo rpp rpr rpt rrc rrk rrp rrr rrt rtc rtk rto rtp rtr rtt tcc tck tco tcp tcr tct tkc tkk tko tkp tkr tkt to- toc tok too top tor tot tpc tpk tpo tpp tpr tpt trc trk tro trp trr trt ttc ttk tto ttp ttr ttt