a-a a-b aaa aab aaf aan aao aar aas aay ab- aba abb abf abn abo abr abs aby af- afa afb aff afn afo afr afs afy an- ana anb anf ann ano anr ans any aoa aob aof aon aoo aor aos ar- ara arb arf arn aro arr ars ary as- asa asb asf asn aso asr ass asy ay- aya ayf ayn ayo ayr ays baa bab baf ban bao bar bas bay bba bbb bbf bbn bbo bbr bbs bby bfa bfb bff bfn bfo bfr bfs bfy bna bnb bnf bnn bno bnr bns boa bob bof bon boo bor bos boy bra brb brf brn bro brr brs bry bsa bsb bsf bsn bso bsr bss bsy by- bya byf byn byo byr bys faa fab faf fan fao far fas fay fba fbb fbf fbn fbo fbr fbs ffa fff ffn ffo ffr ffs ffy fna fnb fnf fnn fnr fns foa fob fof fon foo for fos foy fra frb frf frn fro frr frs fry fsa fsb fsf fsn fso fsr fss fy- fya fyb fyn fyo naa nab naf nan nao nar nas nay nba nbb nbf nbn nbo nbr nbs nfa nfb nff nfn nfo nfr nfs nna nnb nnf nnn nno nns no- noa nob nof non noo nor nos noy nra nrb nrf nrn nro nrr nrs nry nsa nsb nsf nsn nso nsr nss nsy nya nyf nyn nyo nys nyy oaa oab oaf oan oao oar oas ob- oba obb obf obn obo obr obs oby of- ofa ofb off ofn ofo ofr ofs on- ona onb onf onn ono onr ons ony oo- ooa oob oof oon ooo oor oos or- ora orb orf orn oro orr ors ory os- osa osb osf osn oso osr oss oya oyo oys ra- raa rab raf ran rao rar ras ray rba rbb rbf rbn rbo rbr rbs rfa rfb rff rfn rfo rfr rfs rna rnb rnn rno rnr rns rny roa rob rof ron roo ror ros roy rra rrb rrf rrn rrr rrs rsa rsb rsf rsn rso rsr rss ry- rya ryf ryn ryo ryr rys ryy saa sab saf san sao sar sas say sba sbb sbf sbn sbo sbr sbs sby sfa sfb sff sfn sfo sfr sfs sna snb snf snn sno snr sns sny soa sob sof son soo sor sos soy sr- sra srb srf srn sro srr srs sry ss- ssa ssb ssf ssn sso ssr sss sy- sya syb syn syr sys yaa yab yaf yan yao yar yas yay ybf ybr ybs yby yfa yff yfr yfs yna ynn yns yny yob yof yon yoo yor yos yoy yra yrf yrn yro yrs ysa ysb yso ysr yss ysy yyb yyf yys yyy