c-- ccc ccd cck cco ccp ccr cct cdc cdd cdk cdo cdp cdr cdt ckc ckd cko ckt co- coc cod cok coo cop cor cot cpc cpd cpk cpo cpp cpr cpt crc crd crk cro crp crr crt ctc ctd ctk cto ctp ctr ctt dcc dcd dck dco dcp dcr dct ddc ddd ddk ddo ddp ddr ddt dkc dkk dko dkp dkr dkt doc dod dok doo dop dor dot dpc dpd dpk dpo dpp dpr dpt drc drd drk dro drp drr drt dtc dtd dtk dto dtp dtr dtt k-t kcc kcd kck kcp kcr kct kdc kdk kdo kdp kdr kdt kkc kkk kkp kkr kkt koc kod kok koo kop kor kot kpc kpd kpk kpo kpp kpr kpt krc krd krk kro krp krr krt ktc ktk kto ktp ktr ktt oc- occ ocd ock oco ocp ocr oct odc odd odo odp odr odt okc okd okk oko okp okr oo- ooc ood ook ooo oop oor oot op- opc opd opk opo opp opr opt or- orc ord ork oro orp orr ort ot- otc otd otk oto otp otr ott p-p pcc pcd pck pco pcp pcr pct pdc pdd pdk pdo pdp pdr pdt pkc pkd pko pkp pkr pkt poc pod pok poo pop por pot ppc ppd ppk ppo ppp ppr ppt prc prd prk pro prp prr prt pt- ptc ptd ptk pto ptp ptr ptt rcc rcd rco rcp rcr rct rdc rdd rdo rdp rdr rdt rkc rkk rko rkp rkt roc rod rok roo rop ror rot rpc rpd rpk rpo rpp rpr rpt rrc rrd rrk rrp rrr rrt rtc rtd rtk rto rtp rtr rtt tcc tcd tck tco tcp tcr tct tdc tdd tdk tdo tdp tdr tdt tkc tkk tko tkp tkr tkt to- toc tod tok too top tor tot tpc tpd tpk tpo tpp tpr tpt trc trd trk tro trp trr trt ttc ttd ttk tto ttp ttr ttt