a-a a-b a-c aaa aab aac aah aak aao aap aas ab- aba abb abc abh abk abo abp abs ac- aca acb acc ach ack aco acp acs aha ahb ahc ahh ahk aho ahp ahs aka akb akc akh akk ako akp aks aoa aob aoc aoh aok aoo aop aos ap- apa apb apc aph apk apo app aps as- asa asb asc ash ask aso asp ass b-p baa bab bac bah bak bao bap bas bba bbb bbc bbh bbk bbo bbp bbs bca bcb bcc bch bck bco bcp bcs bha bhb bhc bhh bhk bho bhp bhs bka bkb bkc bkk bko bkp bks boa bob boc boh bok boo bop bos bpa bpb bpc bph bpo bpp bps bsa bsb bsc bsh bsk bso bsp bss c-- caa cab cac cah cak cao cap cas cba cbb cbc cbh cbk cbo cbp cbs cca ccb ccc cch cck cco ccp ccs ch- cha chb chc chh chk cho chp chs cka ckb ckc ckh cko cks co- coa cob coc coh cok coo cop cos cpa cpb cpc cph cpk cpo cpp cps csa csb csc csh csk cso csp css haa hab hac hah hak hao hap has hba hbb hbc hbh hbk hbo hbp hbs hca hcb hcc hch hck hco hcp hcs hha hhb hhc hhh hhk hho hhp hhs hka hkb hkh hkk hko hkp hks hoa hob hoc hoh hok hoo hop hos hpa hpb hpc hph hpk hpo hpp hps hsa hsb hsc hsh hsk hsp hss ka- kaa kab kac kah kak kao kap kas kba kbb kbc kbh kbk kbo kbp kbs kca kcb kcc kch kck kcp kcs kha khh khk kho khs kkb kkc kkh kkk kkp kks koa kob koc koh kok koo kop kos kpa kpc kph kpk kpo kpp kps ksa ksb ksc ksh ksk kso ksp kss oaa oab oac oah oak oao oap oas ob- oba obb obc obh obk obo obp obs oc- oca ocb occ och ock oco ocp ocs oha ohc ohh oho ohp ohs oka okb okc okk oko okp oks oo- ooa oob ooc ooh ook ooo oop oos op- opa opb opc oph opk opo opp ops os- osa osb osc osh osk oso osp oss p-p paa pab pac pah pak pao pap pas pba pbb pbc pbk pbo pbp pbs pca pcb pcc pch pck pco pcp pcs pha phb phc phk pho php phs pka pkb pkc pko pkp pks poa pob poc poh pok poo pop pos ppa ppb ppc pph ppk ppo ppp pps ps- psa psb psc psh psk pso psp pss saa sab sac sah sak sao sap sas sba sbb sbc sbh sbk sbo sbp sbs sca scb scc sch sck sco scp scs sh- sha shb shc shh shk sho shp shs sk- ska skb skc skh skk sko skp sks soa sob soc soh sok soo sop sos spa spb spc sph spk spo spp sps ss- ssa ssb ssc ssh ssk sso ssp sss