a-a a-c aaa aac aak aao aap aas ac- aca acc ack aco acp acs aka akc akk ako akp aks aoa aoc aok aoo aop aos ap- apa apc apk apo app aps as- asa asc ask aso asp ass c-- caa cac cak cao cap cas cca ccc cck cco ccp ccs cka ckc cko cks co- coa coc cok coo cop cos cpa cpc cpk cpo cpp cps csa csc csk cso csp css ka- kaa kac kak kao kap kas kca kcc kck kcp kcs kkc kkk kkp kks koa koc kok koo kop kos kpa kpc kpk kpo kpp kps ksa ksc ksk kso ksp kss oaa oac oak oao oap oas oc- oca occ ock oco ocp ocs oka okc okk oko okp oks oo- ooa ooc ook ooo oop oos op- opa opc opk opo opp ops os- osa osc osk oso osp oss p-p paa pac pak pao pap pas pca pcc pck pco pcp pcs pka pkc pko pkp pks poa poc pok poo pop pos ppa ppc ppk ppo ppp pps ps- psa psc psk pso psp pss saa sac sak sao sap sas sca scc sck sco scp scs sk- ska skc skk sko skp sks soa soc sok soo sop sos spa spc spk spo spp sps ss- ssa ssc ssk sso ssp sss