a-a a-b a-t aaa aab aao aap aas aat aay ab- aba abb abo abp abs abt aby aoa aob aoo aop aos aot ap- apa apb apo app aps apt apy as- asa asb aso asp ass ast asy at- ata atb ato atp ats att ay- aya ayo ayp ays ayt b-p baa bab bao bap bas bat bay bba bbb bbo bbp bbs bbt bby boa bob boo bop bos bot boy bpa bpb bpo bpp bps bpt bpy bsa bsb bso bsp bss bst bsy bta btb bto btp bts btt bty by- bya byo byp bys byt oaa oab oao oap oas oat ob- oba obb obo obp obs obt oby oo- ooa oob ooo oop oos oot op- opa opb opo opp ops opt opy os- osa osb oso osp oss ost ot- ota otb oto otp ots ott oya oyo oys p-p paa pab pao pap pas pat pay pba pbb pbo pbp pbs pbt pby poa pob poo pop pos pot poy ppa ppb ppo ppp pps ppt ps- psa psb pso psp pss pst psy pt- pta ptb pto ptp pts ptt pty py- pya pyb pyo pys pyt saa sab sao sap sas sat say sba sbb sbo sbp sbs sbt sby soa sob soo sop sos sot soy spa spb spo spp sps spt spy ss- ssa ssb sso ssp sss sst sta stb sto stp sts stt sty sy- sya syb syp sys syt taa tab tao tap tas tat tay tba tbb tbo tbp tbs tbt to- toa tob too top tos tot toy tpa tpb tpo tpp tps tpt tsa tsb tso tsp tss tst tsy tta ttb tto ttp tts ttt tty tya tyo typ tys tyt yaa yab yao yap yas yat yay ybp ybs yby yob yoo yop yos yot yoy ypa ypo yps ysa ysb yso ysp yss yst ysy yta yto ytp yts ytt yyb yys yyt yyy