a-a a-b a-c aaa aab aac aan aao aar aas aay ab- aba abb abc abn abo abr abs aby ac- aca acb acc acn aco acr acs acy an- ana anb anc ann ano anr ans any aoa aob aoc aon aoo aor aos ar- ara arb arc arn aro arr ars ary as- asa asb asc asn aso asr ass asy ay- aya ayc ayn ayo ayr ays baa bab bac ban bao bar bas bay bba bbb bbc bbn bbo bbr bbs bby bca bcb bcc bcn bco bcr bcs bcy bna bnb bnc bnn bno bnr bns boa bob boc bon boo bor bos boy bra brb brn bro brr brs bry bsa bsb bsc bsn bso bsr bss bsy by- bya byc byn byo byr bys c-- caa cab cac can cao car cas cay cba cbb cbc cbn cbo cbr cbs cby cca ccb ccc ccn cco ccr ccs cn- cna cnb cnc cnn cno cnr cns cny co- coa cob coc con coo cor cos coy cra crb crc crn cro crr crs cry csa csb csc csn cso csr css csy cya cyb cyc cyn cyo cyr cys naa nab nac nan nao nar nas nay nba nbb nbc nbn nbo nbr nbs nca ncb ncc ncn nco ncr ncs nna nnb nnc nnn nno nns no- noa nob noc non noo nor nos noy nra nrb nrc nrn nro nrr nrs nry nsa nsb nsc nsn nso nsr nss nsy nya nyc nyn nyo nys nyy oaa oab oac oan oao oar oas ob- oba obb obc obn obo obr obs oby oc- oca ocb occ ocn oco ocr ocs on- ona onb onc onn ono onr ons ony oo- ooa oob ooc oon ooo oor oos or- ora orb orc orn oro orr ors ory os- osa osb osc osn oso osr oss oya oyo oys ra- raa rab rac ran rao rar ras ray rba rbb rbc rbn rbo rbr rbs rca rcb rcc rcn rco rcr rcs rna rnb rnc rnn rno rnr rns rny roa rob roc ron roo ror ros roy rra rrb rrc rrn rrr rrs rsa rsb rsc rsn rso rsr rss ry- rya ryc ryn ryo ryr rys ryy saa sab sac san sao sar sas say sba sbb sbc sbn sbo sbr sbs sby sca scb scc scn sco scr scs sna snb snc snn sno snr sns sny soa sob soc son soo sor sos soy sr- sra srb src srn sro srr srs sry ss- ssa ssb ssc ssn sso ssr sss sy- sya syb syc syn syr sys yaa yab yac yan yao yar yas yay ybc ybr ybs yby yca ycc yco ycs ycy yna ynn yns yny yob yoc yon yoo yor yos yoy yra yrc yrn yro yrs ysa ysb ysc yso ysr yss ysy yyb yyc yys yyy