a-a a-b aaa aab aak aao aap aas aay ab- aba abb abk abo abp abs aby aka akb akk ako akp aks aoa aob aok aoo aop aos ap- apa apb apk apo app aps apy as- asa asb ask aso asp ass asy ay- aya ayk ayo ayp ays b-p baa bab bak bao bap bas bay bba bbb bbk bbo bbp bbs bby bka bkb bkk bko bkp bks boa bob bok boo bop bos boy bpa bpb bpo bpp bps bpy bsa bsb bsk bso bsp bss bsy by- bya byk byo byp bys ka- kaa kab kak kao kap kas kay kba kbb kbk kbo kbp kbs kkb kkk kkp kks kky koa kob kok koo kop kos koy kpa kpk kpo kpp kps ksa ksb ksk kso ksp kss kya kyo kyp kys oaa oab oak oao oap oas ob- oba obb obk obo obp obs oby oka okb okk oko okp oks oo- ooa oob ook ooo oop oos op- opa opb opk opo opp ops opy os- osa osb osk oso osp oss oya oyo oys p-p paa pab pak pao pap pas pay pba pbb pbk pbo pbp pbs pby pka pkb pko pkp pks pky poa pob pok poo pop pos poy ppa ppb ppk ppo ppp pps ps- psa psb psk pso psp pss psy py- pya pyb pyk pyo pys saa sab sak sao sap sas say sba sbb sbk sbo sbp sbs sby sk- ska skb skk sko skp sks sky soa sob sok soo sop sos soy spa spb spk spo spp sps spy ss- ssa ssb ssk sso ssp sss sy- sya syb syk syp sys yaa yab yak yao yap yas yay ybp ybs yby yka ykk yob yok yoo yop yos yoy ypa ypo yps ysa ysb ysk yso ysp yss ysy yyb yys yyy