a-a a-c aaa aac aak aao aap aar ac- aca acc ack aco acp acr aka akc akk ako akp akr aoa aoc aok aoo aop aor ap- apa apc apk apo app apr ar- ara arc ark aro arp arr c-- caa cac cak cao cap car cca ccc cck cco ccp ccr cka ckc cko co- coa coc cok coo cop cor cpa cpc cpk cpo cpp cpr cra crc crk cro crp crr ka- kaa kac kak kao kap kar kca kcc kck kcp kcr kkc kkk kkp kkr koa koc kok koo kop kor kpa kpc kpk kpo kpp kpr kra krc krk kro krp krr oaa oac oak oao oap oar oc- oca occ ock oco ocp ocr oka okc okk oko okp okr oo- ooa ooc ook ooo oop oor op- opa opc opk opo opp opr or- ora orc ork oro orp orr p-p paa pac pak pao pap par pca pcc pck pco pcp pcr pka pkc pko pkp pkr poa poc pok poo pop por ppa ppc ppk ppo ppp ppr pra prc prk pro prp prr ra- raa rac rak rao rap rar rca rcc rco rcp rcr rkc rkk rko rkp roa roc rok roo rop ror rpa rpc rpk rpo rpp rpr rra rrc rrk rrp rrr